2AXC

Crystal structure of ColE7 translocation domain

Summary for 2AXC

• Entry DOI: 10.2210/pdb2axc/pdb
• Related: 1M08 7CEI
• Descriptor: Colicin E7, SULFATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: colicin, translocation domain, hydrolase
• Biological source: Escherichia coli str. K12 substr.
• Total number of polymer chains: 1
• Total formula weight: 27775.58

Authors

Cheng, Y.S.,Shi, Z.,Doudeva, L.G.,Yang, W.Z.,Chak, K.F.,Yuan, H.S. (deposition date: 2005-09-04, release date: 2006-03-14, Last modification date: 2024-10-23)

Primary citation

Cheng, Y.S.,Shi, Z.,Doudeva, L.G.,Yang, W.Z.,Chak, K.F.,Yuan, H.S.
High-resolution crystal structure of a truncated ColE7 translocation domain: implications for colicin transport across membranes
J.Mol.Biol., 356:22-31, 2006

PubMed Abstract: ColE7 is a nuclease-type colicin released from Escherichia coli to kill sensitive bacterial cells by degrading the nucleic acid molecules in their cytoplasm. ColE7 is classified as one of the group A colicins, since the N-terminal translocation domain (T-domain) of the nuclease-type colicins interact with specific membrane-bound or periplasmic Tol proteins during protein import. Here, we show that if the N-terminal tail of ColE7 is deleted, ColE7 (residues 63-576) loses its bactericidal activity against E.coli. Moreover, TolB protein interacts directly with the T-domain of ColE7 (residues 1-316), but not with the N-terminal deleted T-domain (residues 60-316), as detected by co-immunoprecipitation experiments, confirming that the N-terminal tail is required for ColE7 interactions with TolB. The crystal structure of the N-terminal tail deleted ColE7 T-domain was determined by the multi-wavelength anomalous dispersion method at a resolution of 1.7 angstroms. The structure of the ColE7 T-domain superimposes well with the T-domain of ColE3 and TR-domain of ColB, a group A Tol-dependent colicin and a group B TonB-dependent colicin, respectively. The structural resemblance of group A and B colicins implies that the two groups of colicins may share a mechanistic connection during cellular import.

PubMed: 16360169
DOI: 10.1016/j.jmb.2005.11.056

Experimental method

X-RAY DIFFRACTION (1.7 Å)