Format

Send to

Choose Destination
Structure. 2014 Jul 8;22(7):1055-62. doi: 10.1016/j.str.2014.05.008. Epub 2014 Jun 26.

Lateral opening and exit pore formation are required for BamA function.

Author information

1
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
2
School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA.
3
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: skbuchan@helix.nih.gov.

Abstract

The outer membrane of Gram-negative bacteria is replete with a host of β-barrel outer membrane proteins (OMPs). Despite serving a variety of essential functions, including immune response evasion, the exact mechanism of OMP folding and membrane insertion remains largely unclear. The β-barrel assembly machinery complex is required for OMP biogenesis. Crystal structures and molecular dynamics (MD) simulations of the central and essential component, BamA, suggest a mechanism involving lateral opening of its barrel domain. MD simulations reported here reveal an additional feature of BamA: a substrate exit pore positioned above the lateral opening site. Disulfide crosslinks that prevent lateral opening and exit pore formation result in a loss of BamA function, which can be fully rescued by the reductant tris(2-carboxyethyl)phosphine. These data provide strong evidence that lateral opening and exit pore formation are required for BamA function.

PMID:
24980798
PMCID:
PMC4100585
DOI:
10.1016/j.str.2014.05.008
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center