3iax
From Proteopedia
The crystal structure of the TolB box of Colicin A in complex with TolB reveals important differences in the recruitment of the common TolB translocation portal used by group A colicins
Structural highlights
FunctionTOLB_ECOLI Involved in the TonB-independent uptake of group A colicins (colicins A, E1, E2, E3 and K). Necessary for the colicins to reach their respective targets after initial binding to the bacteria.[HAMAP-Rule:MF_00671] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedInteraction of the TolB box of Group A colicins with the TolB protein in the periplasm of Escherichia coli cells promotes transport of the cytotoxic domain of the colicin across the cell envelope. The crystal structure of a complex between a 107-residue peptide (TA(1-107)) of the translocation domain of colicin A (ColA) and TolB identified the TolB box as a 12-residue peptide that folded into a distorted hairpin within a central canyon of the beta-propeller domain of TolB. Comparison of this structure with that of the colicin E9 (ColE9) TolB box-TolB complex, together with site-directed mutagenesis of the ColA TolB box residues, revealed important differences in the interaction of the two TolB boxes with an overlapping binding site on TolB. Substitution of the TolB box residues of ColA with those of ColE9 conferred the ability to competitively recruit TolB from Pal but reduced the biological activity of the mutant ColA. This datum explains (i) the difference in binding affinities of ColA and ColE9 with TolB, and (ii) the inability of ColA, unlike ColE9, to competitively recruit TolB from Pal, allowing an understanding of how these two colicins interact in a different way with a common translocation portal in E. coli cells. The crystal structure of the TolB box of colicin A in complex with TolB reveals important differences in the recruitment of the common TolB translocation portal used by group A colicins.,Zhang Y, Li C, Vankemmelbeke MN, Bardelang P, Paoli M, Penfold CN, James R Mol Microbiol. 2010 Feb;75(3):623-36. Epub 2009 Jul 21. PMID:19627502[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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