2YSU

Structure of the complex between BtuB and Colicin E2 receptor binding domain

Summary for 2YSU

• Entry DOI: 10.2210/pdb2ysu/pdb
• Descriptor: Vitamin B12 transporter btuB, Colicin-E2 (2 entities in total)
• Functional Keywords: beta-barrel, coiled-coil, transport protein-hydrolase complex, transport protein/hydrolase
• Biological source: Escherichia coli; More
• Cellular location: Cell outer membrane; Multi-pass membrane protein: P06129
• Total number of polymer chains: 2
• Total formula weight: 81548.90

Authors

Cramer, W.A.,Sharma, O.,Yamashita, E. (deposition date: 2007-04-04, release date: 2007-06-19, Last modification date: 2024-03-13)

Primary citation

Sharma, O.,Yamashita, E.,Zhalnina, M.V.,Zakharov, S.D.,Datsenko, K.A.,Wanner, B.L.,Cramer, W.A.
Structure of the complex of the colicin E2 R-domain and its BtuB receptor. The outer membrane colicin translocon
J.Biol.Chem., 282:23163-23170, 2007

PubMed Abstract: The crystal structure of the complex of the BtuB receptor and the 135-residue coiled-coil receptor-binding R-domain of colicin E3 (E3R135) suggested a novel mechanism for import of colicin proteins across the outer membrane. It was proposed that one function of the R-domain, which extends along the outer membrane surface, is to recruit an additional outer membrane protein(s) to form a translocon for passage colicin activity domain. A 3.5-A crystal structure of the complex of E2R135 and BtuB (E2R135-BtuB) was obtained, which revealed E2R135 bound to BtuB in an oblique orientation identical to that previously found for E3R135. The only significant difference between the two structures was that the bound coiled-coil R-domain of colicin E2, compared with that of colicin E3, was extended by two and five residues at the N and C termini, respectively. There was no detectable displacement of the BtuB plug domain in either structure, implying that colicin is not imported through the outer membrane by BtuB alone. It was concluded that the oblique orientation of the R-domain of the nuclease E colicins has a function in the recruitment of another member(s) of an outer membrane translocon. Screening of porin knock-out mutants showed that either OmpF or OmpC can function in such a translocon. Arg(452) at the R/C-domain interface in colicin E2 was found have an essential role at a putative site of protease cleavage, which would liberate the C-terminal activity domain for passage through the outer membrane translocon.

PubMed: 17548346
DOI: 10.1074/jbc.M703004200

Experimental method

X-RAY DIFFRACTION (3.5 Å)