6gki
Structure of E coli MlaC in Variously Loaded States
Structural highlights
Function[MLAC_ECOLI] Actively prevents phospholipid accumulation at the cell surface. Probably maintains lipid asymmetry in the outer membrane by retrograde trafficking of phospholipids from the outer membrane to the inner membrane. May transfer phospholipid across the periplasmic space and deliver it to the MlaFEDB complex at the inner membrane.[1] Publication Abstract from PubMedThe Mla pathway is believed to be involved in maintaining the asymmetrical Gram-negative outer membrane via retrograde phospholipid transport. The pathway is composed of three components: the outer membrane MlaA-OmpC/F complex, a soluble periplasmic protein, MlaC, and the inner membrane ATPase, MlaFEDB complex. Here, we solve the crystal structure of MlaC in its phospholipid-free closed apo conformation, revealing a pivoting beta-sheet mechanism that functions to open and close the phospholipid-binding pocket. Using the apo form of MlaC, we provide evidence that the inner-membrane MlaFEDB machinery exports phospholipids to MlaC in the periplasm. Furthermore, we confirm that the phospholipid export process occurs through the MlaD component of the MlaFEDB complex and that this process is independent of ATP. Our data provide evidence of an apparatus for lipid export away from the inner membrane and suggest that the Mla pathway may have a role in anterograde phospholipid transport. Evidence for phospholipid export from the bacterial inner membrane by the Mla ABC transport system.,Hughes GW, Hall SCL, Laxton CS, Sridhar P, Mahadi AH, Hatton C, Piggot TJ, Wotherspoon PJ, Leney AC, Ward DG, Jamshad M, Spana V, Cadby IT, Harding C, Isom GL, Bryant JA, Parr RJ, Yakub Y, Jeeves M, Huber D, Henderson IR, Clifton LA, Lovering AL, Knowles TJ Nat Microbiol. 2019 Oct;4(10):1692-1705. doi: 10.1038/s41564-019-0481-y. Epub, 2019 Jun 24. PMID:31235958[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
