The extension of time. To suspend payment I am involved in this failure. To meet every claim. To realize the stock of goods. Briefe an Sdtnlbnct ptjrafen Der Sd? Die ausftel enbe Jorberung. Letter of Recommendation I2. The letter of credit Das 2lccrebttto, ber Krebttbrtef. Duplicate receipt, available but once. Brommer hier habe ich heute als Betrag meiner Rechnung vom 9. Sechshundert Mark Dresden, den Michel hier fiir Rechnung des Herrn I. Kolbe in Stettin , ,. Doppelschein Von Herrn L. Dies bescheinigt Leipzig, den i. Heinrich hier sind uns heute: Lieferschein an einen Spediteur Durch Herrn S.
Schuldschein Ich verspreche hiermit, am 3. Bet bcm lt ed? Pen eigenen ober SoIa-lDed? Of strong verbs only the changing vowels are given unless the whole stem changes. Separable compound verbs are marked with an asterisk, e. Verbs are to be con- jugated with traben unless f. An alphabetic list of strong, mixed and irregular verbs in their uncompounded form will be found on page In the parenthesis following the noun the genitive singular is given first, the nominative plural second. Adjectives and verbs used as nouns will be found under the simple adjective or verb.
The vocabulary gives only the meanings which the words bear in this book. Einfang -[e]s, -"e , m. Equator -s , m.
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Sea of Azof northeast of the Crimea, southern Russia. Ia9cn u, a , erect a booth or tent ; bic 2lugcn -, raise one's eyes. Zlusbau -s , m. Barfftein -[e]s, -e , m. Babemeifter -s, - , m. Baben -s , n. Bagageauf feller -s, - , m. Batjnprojeft -[e]s, -e , n. Batffter -S, -s , m. BaFu -s , n. Ballaft -[e]s, -e , in. Bauen -s, - , m. Banfenbetrieb -[e]s, -e , m. Banffadf -[e]s, ''er , n. Banfier -s, -s , m. Banffvftem -[e]s, -e , w. Banfroefen -s, - , n. Barchent -[e]s, -e , m. Barmen -s , n. Bau -es, -e , m. Baufaftcn -s,'' , m.
Baumeifter -s, - , m. Bayern -s , n. Beamte -n, -n , m. Bebarf -[e]s , m. Bebenfen -s, - , n. Befremben -s , n. Begel r -[e]s , m. Beginn -[e]s , m. Begriff -[e]s, -e , m. Beifall -le]s , m. Beifpiel -[e]s, -e , n. Beneljmen -s , n. Berg -[els, -e , m. Bericht -[els, -e , w. Berlin -s , n. Bcftimmung -, -en , f. Bcftreben -s, 3eftrebungen , n. Betracht -[e]s , m. Betragen -s , n. Betrieb -[e]s,-e , m. Bctriebsfapital -[e]s, -e or -ien , n. Betrug -[e]s , m. Bettler -s, - , m. Bewerber -s, - , m. Be3trf -[e]s, -e , m. Bier -[e]s, -e , n. Bilb -es, -er , n. Btlbn erf -[e]s,-e ,n.
Binnenmeer -[e]s, -e ,n. Biffen -s, - , m. Vtlaii -[e]s, ''er , n. Blauftift -[e]s, -e , m. Bleijitft -[e]s, -e , m. BItcf -[e]s, -e , m. Blumenbeet -[rfs, -e , n. Blufenliemb -[e]s, -en , n. Bogen -s, - , m. Botjmen -s , n. Bolioien -s , n. Boot -es, -e or 'S'6te , n. Borb -[e]s, -e , m. Botantfer -s, - , m. Braftlten -s , n. Bredpetfen -s, - , n. Bremen -s , n. Brennmaterial -[e]s, -ten , n. Breslau -s , n.
Brett -es, -er , n. Brief -[e]s, -e , m. Brief faften -s, - , m. Brief mufter -s, - , n. Briefporto -s, -s or Brillant -en, -en , m. Bruber -s, ' , m. Briiffel -s , n. Bugfprtet -[e]s, -e , n. Bureau -s, -s or -5 , n. Centimeter -s, - , m. Centner -s, - , m. Centra IsBureau -s, s , n.
Cljef -S, -s , m. Civile -5 , n. Cigarrenoerfauf -[e]s, ''e , m. Cigarettenfonfum -[e]s , m. Comptoirbiener -s, - , m. Comptoirift -en, -en , m. ComptoirutenfiUen, pi, office fix- tures. Conto -[s], -5 or Crcbit -[c]s , m. Dadf -[es], ''er , n. Dampfer -s, - , m. Dampf f ran -[e]s, 'e , m. Danf -[e]s , m. Depojlt -S, -en , n. Detail -s, -s , n. Petailltft -en, -en , m. Detailoerfauf -[e]s, ''e , m. X e3ember -s, - m. Diamant -en, -en , w. Diamantfunb -[es], -e , m. Dieb -es, -e , m. Diener -s, - , m. Dienji -es, -e , m. Dtenftbote -n, -n , m. Differenseinroanb -[e]s, ""e , m.
Diftat -[e]s, -e ,? Dinejr -s, -s , n. Direftor -s, -en , m. Pispofltton -, -en , disposition, arrangement, management. Dioan -s, -s or -e , m. Pocf -5, -s , n. Dom -[e]s, -e , m. Dombrunnen -s, - , m. Donnerstag -[e]s, -e , m. Dortmunb -s , n. Drafjt -[e]s, ''e , m. Dresben -s , n. Drucf -[c[s , m. Dunji -es, "e , m. Duplif at -[e]5, -e , n. DupIifatsStempel -s, - , m.. Duftenb -S, -e , n.
Eigner -s, - , m. Eingangshafen -s, ' , m. Etnfommen -s , n. Einfenber -s, - , m. Eintritt -[e]s , m. Eifcn -S, - , n. Element -[e]s, -e , n. Elfenbein -[e]s , n. Enfel -S, - , wi. Entfernung -, -en , f. Entmurf -[e]s, H , m. Erbteil -[e]5, -e , m. Erfolg -[es], -e , m. Erftling -[e]s, -c , m. Er3 -es, -e , n. Esfimo -[s], -S , m. Etabltffement -5, -s , n. Etagere -, -n ,f. Etatsmefen -s , n. Eftborf -5 , n. Europa -'s , n. Exemplar -[e]s, -e , n. Experiment -[els, -e , n. Export -[e]s, -e , m.
Exporteur -5, -e , m.
Ja br if ant -en, -en , m. Jabrifat -[e]s, -e , n. Falliment -[e]s, -s or -e , n. Jroljftnn -[e]s , m. SangfpiU -[e]s, -e , n. Sam -[e]s, -e , n. Sarten -s, '' , m. Sebiet -[e]s, -e , n. SebanFe -ns, -n , m. Sefolge -s, - , n. Segcnbicnfi -es, -e , m. Segenftanb -[e]s, ""e , m. Sefjorfam -[e]s , m.
Stebel -S, - , m. SelbmarFt -[e]s, ''e , m. Selbftiirf -[e]s, -e , n. Selboerluft -[e]s, -e , m. Seleife -s, - , n. Semalbe -s, - , n. Semiife -s, - , n. Seneralpoftamt -[e]s, ''er , n. Senie -s, -s , n. Sefamtn ert -[e]5,-e ,m. SepSrftartf -[e]s, -e , m. Seftabe -s, - , n. Sefted -[e]s, -e , n. Setrappel -s , n. Setrtebe -s, - , n. Seroerbcbetrieb -[e]s, -e , m. Mcminn -[e]s, -e , m. Seipoge -s , n.
Solb -es , n. Srab -[e]s, -e , m. Sraf -en, -en , m. Stamm -[e]s, -e , n. Stan -[e]s, -e , n. Sranit -[e]s , m. Sroglofal -[e]5, -e , n. Srunbfapital -[e]s, -ien , n. Bfalm -[e]s, -e , m. Hamburg -s , n. Kauptfan9be3trf -[e]s, -e , m. Hilfsmittel -s, - , n. Himmel -s, - , m. Irinnen, von -, away. Qintergninb -[e]s , m. Qirtenfeuer -s, - , n.
Qobel -5, - , m. Hoflieferant -en, -en , m. Hort3ont -[ejs, -e , m. Kabel -s, - , n. Kabelbampfer -s, - , m. Kaffee -s, -s , m. Kaffeetjanbel -s , m. Kaifer -s, - , m. Kalam -s, -s , m. Kamerab -en, -en , m. Kaminfeuer -s, - , n. Kanabier -s, - , m. Kap -5, -s , n. Kapitalift -en, -en , m. Kapitalftocf -s , m. Karpfen -s, - , m. Karuffell -[e]s, -e or-s , n. KaruffellsBepfter -s, - , m. Kaffenbote -n, -n , m. Kaffen-Diebftatjl -[e]s,''e , m. Kaffenmefen -s,- , n. Kaffierer -s, - , m.
Kafpererpojlen -s, - , m. Kajlen -s, - , m. FauffrSftig, able to buy. Ketjl -s , w. Keller -5, - , m. Kellner -s, - , m. Keflfel -5, - , m. Kiel -[e]s, -e , m. Kilogramm -5, -e , n. Kilometer -s, - , m. Ktlometerljeft -[ejs, -e , n.. Ktnb -[e]5, -er , n. Kinberfleib -[e]s, -er , n. Kleib -te]s, -er , n. Kleiber f offer -s, - , m. Kleiberftoff -fels, -e , w. Kletberreiniger -s, - , m.
Kleingelb -[e]s , n. Knabe -n, -n , m. KnabenFIetber, pL, boys' clothing. Knie -[e]s, -[e] , n. Knopf -[e]s, ''c , m. Knoten -s , m. Knotenpunft -[ejs, -ej, m. Koburg -s , n. Koffer -5, - , m. Kommanbo -5, -s , n. Kommtffionslager -s, - , w. Kompagnon -s, -s , m. Konbufteur -[e]s,-e , m.
Konfurrent -en, -en , m. Konfurren3Fampf -[c]s,''e , m. Konoffement -[e]s, -e , n. Konfolbrett -[e]s,-er , n. Konftantiiiopel -s , n. Konful -5, -n , m. Konfulat -[e]5, -e , n. Konfum -[e]s , m. Konfument -en, -en , m. Konfumlanb -[e]s, ''er , w. Kontinent -[els, -e , m. Kontingent -[e]s,-e , n. Kopf -[e]s, ""e , m.
Korrefponbent -en, -en , w. Korfett -[e]s, -e or -s , w. Koften, pi, expenses, costs. Koftiim -[e]s, -e , n. Kragen -s, - , m. Kranfe -n, -n , m.. Krebitor -s, -en , m. Kreibejiift -[eJs, -e , m. Kreuj C-es, -e , n. Kribar -[e]s, -e , m. Krieg -[e]s, -e , m. Kronprtn3 -en, -en ,m. Kunbe -n, -n , m. Kunjilaben -s, "" , m.
Original Research ARTICLE
KunfkroerF -[e]s,-e , n. Kupfer -s , w. Cagerift -en, -en , m. Harib -[e]s, ''er , n. Ceitcr -s, - , m.
Icfcn a, e , read. Cujus - , m. IRagbeburg -s , n. ITTagen -s, - , m. Vfiai - or -[c]s, -[e]n , m. UTannljeim -s , n. Utantei -s, '' , m. UtarFjiein -[e]s, -e m. JXtaxh -[e]s, ''e , m. IHatrofe -n, -n , m. IRauermerf -[e]s, -e , n. Maulbeerbaum -[els, ''e , m. Utebifament -[e]s, -e , n. Ifieer -[e]s, -e , n. IReijler -s, - , m. Uteter -s, - , m.
IHobeU -[e]s, -e , w. UTonat -[e]s, -e , m. IRonopoIftaat -[e]s,-en , m. IRorgen -s, - , m. IHungof utter -s , n. IHuffeltn -[e]s, -e , m. IHufter -S, - , n. Htut -[e]s , m. Haturprobuft -[els, -e , n. However, one of these, which provides only a single ligand to iron, projects off the iron center and distorts its size and symmetry The face of the FeEnt iron complex is relatively flat 23 , and this feature may be requisite for binding.
The lack of siderophore nutrition by FeAgroA concurs with the results of Ong et al. The different binding capacities of FeEnt and FeTRENCAM must stem from structural variations in the two siderophores that center on the presence of a tertiary amine in the synthetic siderophore. This basic group carries a positive charge at neutrality, while the macrocyclic ring of FeEnt is uncharged. One explanation of these data is that, like all the structurally characterized porins 12 , 26 , 50 , 63 , FepA exists in vivo as a trimer that accommodates three molecules of FeEnt but only a single molecule of FeTRENCAM.
The receptor protein binds the iron center of FeTRENCAM and, although the positive charge on the back of the molecule did not affect the affinity of its adsorption, it may create a charge repulsion barrier that prevents subsequent adsorption of another positively charged chelate, thus reducing binding capacity. An analytical comparison of FeEnt and colicins binding to FepA 39 showed similar results: Although another ligand-gated porin, the ferrichrome receptor, was purified in monomeric form 8 , several independent lines of evidence now support the trimeric structure of FepA in vivo.
Relevant to this point, our transport data demonstrate, for the first time, sigmoidal uptake kinetics for FeEnt. When analyzed as allosteric reactions, the transport data yielded Hill coefficients of approximately 3, consistent with a native FepA protein that contains three interacting, cooperative binding sites. These may be equivalent sites on the monomers of a trimer, or three distinct sites on a monomeric protein.
In either case, our data indicate that multiple binding sites within FepA function allosterically during FeEnt transport. The comparable affinities of the five gram-negative bacterial outer membrane transport proteins for FeEnt was unexpected. Against a background of broad overall genetic diversity, the four species manifested a remarkable preservation of avidity for FeEnt. While the structural genes, regulatory systems, and transport components of these organisms adapted to their individual biological needs, the specificity of their outer membrane receptors persevered essentially unchanged.
The overall variation in the proteins themselves, from E. The evolution of bacterial outer membrane proteins occurs most rapidly in their surface loops 22 , 48 , and the FeEnt binding site illustrates conservation of a functional domain within an overall framework of high sequence variability. The retention of a FeEnt transport system in Pseudomonas and Bordetella , with modifications of its regulation, illustrates the importance of iron acquisition in bacterial pathogenesis. In both of these disease-causing organisms, the regulatory system has changed from negative and repressible to positive and inducible.
That is, the presence of enterobactin induces synthesis of the receptor for its ferric complex, an advantageous strategy for organisms that infect tissues cohabited by enterobactin-secreting bacteria. Transport of FeEnt into P. Although prior work with a Salmonella model system questioned the relationship between FeEnt-mediated iron acquisition and bacterial pathogenesis 6 , an overwhelming amount of data now links iron and virulence. In the context of these examples relating iron to infection, the inducible FeEnt transport systems of Bordetella and Pseudomonas emphasize the value of siderophores to bacteria: FeEnt is such a ubiquitous and potent iron complex that these pathogenic bacteria have evolved to steal it from their competitors.
Although plasmid effects are a potential explanation for the poor function of foreign proteins in E. Both Salmonella proteins bound FeEnt with high affinity, providing evidence of properly folded, biologically active conformations. The likely explanation for their inferiority is that additional components of the FeEnt uptake systems of Salmonella and Escherichia are sufficiently different to impair the transport reaction. On the other hand, E. The multicopy plasmid effected a two- to threefold higher expression level expression than the chromosomal system, but the increase did not cause a higher rate of FeEnt uptake.
These calculations suggest that the higher expression levels encoded by the plasmid exceeded the overall capabilities of the transport complex. The deficiencies in the plasmid system may ensue from inadequate amounts of one or more of the other required components of the cell envelope, including FepB, TonB, or another as-yet-unidentified molecule. At present, however, we cannot fully explain the lower activity of the plasmid-based FepA proteins. We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail.
We do not retain these email addresses. Skip to main content. Padmamalini Thulasiraman , Salete M. Newton , Jide Xu , Kenneth N. Montague , Phillip E. View inline View popup. Accepted 8 October Membrane, soluble, and periplasmic fractions. Demonstration of enzymatic hydrolysis of enterobactin and its iron complex. Kinetics and mechanism of iron removal from transferrin by enterobactin and synthetic tricatechols. Siderophore synthesis in Klebsiella pneumoniae and Shigella sonnei during iron deficiency. Recognition and transport of natural synthetic siderophores by microbes.
No significant change in correlation time data not shown was observed when the lobes were treated independently, indicating that the lobes move together in solution. Arg in both of the FepD homodimer chains is in a homologous position to Arg from both BtuC homodimer chains, shown previously to be important for interactions with BtuF A comparison of the BtuC loop, which interacts with BtuF, and a similarly positioned FepD surface loop revealed differences in the electrostatic composition Fig.
In BtuC, the loops are composed of both basic and acidic amino acids, whereas in FepD the purported FepB-interacting loop is primarily acidic Fig. In A , conserved Glu residues and positions are shown for apo- yellow and holo-FepB red on the holo-FepB structure. A space-filling format is used to represent the conserved Glu residues and the flexible loop region residues — of apo- white and holo-FepB dark gray. In this study, NMR spin relaxation experiments were used to evaluate changes in FepB dynamics in the presence and absence of ligand. This is particularly relevant for PBPs, as opening and closing motions are important for both ligand binding and release Fig.
For type I and II PBPs, it has been suggested that the rigidity of the hinge region, which is strongly influenced by the hydrogen bonding network between hinge elements, becomes more ordered upon ligand binding leading to large scale opening-closing motions These movements originate from minor changes e.
This results in a minor displacement of the N-lobe toward the C-lobe but does not lead to any significant domain-closing motions. Moreover, submission of the lowest energy apo- and holo-FepB structures to the Dyndom server 81 did not reveal any dynamic hinge-bending domain motions associated with ligand binding. The N-lobe of both forms of each protein was aligned prior to analysis. PBPs also experience changes to the interface between their two lobes upon ligand binding. In types I e.
In contrast, both the apo and holo forms of type III PBPs have extensive interlobe contacts, and ligand binding appears to produce subtle rearrangements to this interface. Structural differences that arise from changes to the intermolecular interactions at this region were evaluated by assessing the interlobe SASA Table 2 Changes to the interlobe interface during the transition between apo and holo forms appears to be important in some type III PBPs for accommodating the structural changes associated with ligand binding, and they could have a role in regulating the opening-closing domain motions.
Interestingly, apo-BtuF extracted from the complex with its ABC transporter BtuCD experiences a decrease in interlobe SASA, indicating that its lobes are spread further apart in complex with the transporter than the isolated apo form. The notable exception is BtuF, which 20 experiences an expansion of its binding pocket upon cyanocobalamin interaction Table 2. An increase or reduction in binding pocket SASA is related to the size of the ligand, the depth of binding, and structural features of the protein. Interestingly, Arg is part of a structural insert residues 72—78 that is absent in ViuP Fig.
Although two of three basic coordinating residues differ between FepB and ViuP, there exists significant similarity in their binding pocket composition. CeuE and YclQ and also use a Tyr residue to help coordinate ligand binding. Taken together, our NMR data strongly suggest that FepB possesses a ligand binding pocket similar to that of ViuP, with the primary difference being residues 72—78, which provide a coordinating residue i.
A structure-based sequence alignment of PBPs that bind catecholate-type siderophores. Numbering based on alignment position and residue numbers are shown above and on the right of the sequences, respectively. The sequence alignment was constructed using 3D-Coffee From our NMR relaxation experiments, the flexible loop region — in apo-FepB becomes more ordered upon ligand binding.
This increased rigidity likely originates from direct interactions with GaEnt, as observed with Ile Fig. The movement and direct involvement of C-lobe loop residues in ligand binding has been observed previously for the type III substrate-binding proteins HtsA 90 and SirA 91 from Staphylococcus aureus. B-factor analysis of ViuP suggests that it may also possess a flexible C-lobe loop region residues — , which becomes more rigid upon ligand binding but does not change position.
This structure confirms our ligand binding findings and shows that Arg, Arg, and Arg are the basic trio of residues involved in FeEnt coordination and that the methyl groups of Val, Val, and Ile contribute to ligand binding. The apo FepB crystal structure remains elusive, which is required for understanding the binding mode and mechanism of FeEnt recognition.
This interaction is characterized by salt-bridge contacts formed between conserved acidic residues at the apices of each PBP lobe and basic residues on the periplasmic exposed surface of the transporter 8. The movement of Glu appears to be related to the ordering of residues within the large loop region residues — of FepB, which occurs upon ligand binding and may help to position Glu for contact with FepD.
Interestingly, homology modeling of FepD reveals the presence of acidic loops that would be in position to interact with the predominantly basic ordered loop and binding pocket of FepB to potentially disrupt FeEnt binding in a similar manner as thought to be the case for cyanocobalamin release and BtuF-BtuCD Fig. This result also points to an important role for protein dynamics in PBP-transporter interactions and suggests a mechanism through which FepD can trigger release of FeEnt from FepB, despite its strong ligand binding affinity. In this study, the mapping of siderophore binding to FepB by a modified reverse methyl-cross saturation NMR experiment was particularly effective in highlighting residues that make hydrophobic contacts with the ligand; this is an effective technique that can be applied to other studies of PBP-ligand interactions.
C-lobe loop dynamics were shown to have a significant role in ligand binding in FepB, which highlights the usefulness of our solution NMR approach to studying PBPs. For regions —, —, and 77—81 within the larger region of residues 70—94 of FepB, the movement of these loops is expected to provide critical contacts with the ligand. The additional flexibility of PBPs as suggested by this study of FepB is likely also important for ligand dissociation.
The role of protein dynamics in ligand release from the PBP to its cognate cytoplasmic membrane ABC transporter is currently not well understood. As suggested by the more open BtuF structure in complex with its cytoplasmic membrane ABC transporter, BtuCD, protein dynamics may play an important role in enabling the C-lobe of BtuF to pivot and spread apart leading to release of cyanocobalamin We are grateful to the late Dr.
Peter Tieleman for the use of the cluster computing resources in calculating the FepB structures. We also thank Dr. Hiroaki Ishida for helpful discussions and testing of the methyl cross-saturation experiments and Dr. Ted Johanson for construction of the E. You'll be in good company. Journal of Lipid Research. To whom correspondence should be addressed: Biochemistry Research Group, Dept.
Previous Section Next Section. Protein Expression and Purification Mature fepB 33 without its signal sequence was cloned into pETb Novagen and expressed with an N-terminal His 10 tag as described previously Fluorescence Spectroscopy Fluorescence titration experiments of FepB with FeEnt or GaEnt were performed on a Varian Cary Eclipse fluorescence spectrophotometer with excitation and emission slit widths set to 5 nm. Methyl Cross-saturation Reverse methyl cross-saturation experiments were measured on a 0. Data Processing and Analysis Absolute chemical shift changes upon ligand binding were examined on a per residue basis using a combined chemical shift difference according to Mulder et al.
In this window In a new window. Methyl Cross-saturation NMR cross-saturation experiments are an indispensable tool for examining the interface of protein-protein interaction complexes FepB Dynamics Backbone 15 N relaxation measurements to examine fast ps to ns time scale backbone dynamics were performed on apo- and holo-FepB Fig.
Biometals 23 , — CrossRef Medline Google Scholar. Biochemistry 37 , — Acta , — Biochemistry 32 , —