1c5k | pdb_00001c5k
THE STRUCTURE OF TOLB, AN ESSENTIAL COMPONENT OF THE TOL-DEPENDENT TRANSLOCATION SYSTEM AND ITS INTERACTIONS WITH THE TRANSLOCATION DOMAIN OF COLICIN E9
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 Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: E colicin proteins have three functional domains, each of which is implicated in one of the stages of killing Escherichia coli cells: receptor binding, translocation and cytotoxicity. The central (R) domain is responsible for receptor-binding activity whereas the N-terminal (T) domain mediates translocation, the process by which the C-terminal cytotoxic domain is transported from the receptor to the site of its cytotoxicity. The translocation of enzymatic E colicins like colicin E9 is dependent upon TolB but the details of the process are not known. RESULTS: We have demonstrated a protein-protein interaction between the T domain of colicin E9 and TolB, an essential component of the tol-dependent translocation system in E. coli, using the yeast two-hybrid system. The crystal structure of TolB, a procaryotic tryptophan-aspartate (WD) repeat protein, reveals an N-terminal alpha + beta domain based on a five-stranded mixed beta sheet and a C-terminal six-bladed beta-propeller domain. CONCLUSIONS: The results suggest that the TolB-box residues of the T domain of colicin E9 interact with the beta-propeller domain of TolB. The protein-protein interactions of other beta-propeller-containing proteins, the yeast yPrp4 protein and G proteins, are mediated by the loops or outer sheets of the propeller blades. The determination of the three-dimensional structure of the T domain-TolB complex and the isolation of mutations in TolB that abolish the interaction with the T domain will reveal fine details of the protein-protein interaction of TolB and the T domain of E colicins. The structure of TolB, an essential component of the tol-dependent translocation system, and its protein-protein interaction with the translocation domain of colicin E9.,Carr S, Penfold CN, Bamford V, James R, Hemmings AM Structure. 2000 Jan 15;8(1):57-66. PMID:10673426[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
