Subunit interactions in ABC transporters: aconserved sequence in hydrophobic membrane proteins of periplasmic permeases defines an important site of interaction with the ATPase subunits
Open Access
- 1 June 1997
- journal article
- research article
- Published by Springer Nature in The EMBO Journal
- Vol. 16 (11) , 3066-3077
- https://doi.org/10.1093/emboj/16.11.3066
Abstract
The cytoplasmic membrane proteins of bacterial binding protein‐dependent transporters belong to the superfamily of ABC transporters. The hydrophobic proteins display a conserved, at least 20 amino acid EAA‐‐‐G‐‐‐‐‐‐‐‐‐I‐LP region exposed in the cytosol, the EAA region. We mutagenized the EAA regions of MalF and MalG proteins of the Escherichia coli maltose transport system. Substitutions at the same positions in MalF and MalG have different phenotypes, indicating that EAA regions do not act symmetrically. Mutations in malG or malF that slightly affect or do not affect transport, determine a completely defective phenotype when present together. This suggests that EAA regions of MalF and MalG may interact during transport. Maltose‐negative mutants fall into two categories with respect to the cellular localization of the MalK ATPase: in the first, MalK is membrane‐bound, as in wild‐type strains, while in the second, it is cytosolic, as in strains deleted in the malF and malG genes. From maltose‐negative mutants of the two categories, we isolated suppressor mutations within malK that restore transport. They map mainly in the putative helical domain of MalK, suggesting that EAA regions may constitute a recognition site for the ABC ATPase helical domain.Keywords
This publication has 42 references indexed in Scilit:
- Functional Dissection of P-glycoprotein Nucleotide-binding Domains in Chimeric and Mutant ProteinsPublished by Elsevier ,1995
- A common topology of proteins catalyzing ATP‐triggered reactionsFEBS Letters, 1995
- Genetic Analysis of Periplasmic Binding Protein Dependent Transport in Escherichia coliJournal of Molecular Biology, 1993
- ABC Transporters: From Microorganisms to ManAnnual Review of Cell Biology, 1992
- Characterization of side-directed mutations in conserved domains of MalK, a bacterial member of the ATP-binding cassette (ABC) familyFEBS Letters, 1992
- Bacterial periplasmic permeases belong to a family of transport proteins operating from Escherichia coli to human: Traffic ATPasesFEMS Microbiology Letters, 1990
- Allele-specific malE mutations that restore interactions between maltose-binding protein and the inner-membrane components of the maltose transport systemJournal of Molecular Biology, 1988
- Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.Proceedings of the National Academy of Sciences, 1979
- Electrophoretic resolution of the ‘major outer membrane protein’ of Escherichia coli K12 into four bandsFEBS Letters, 1975
- Reaction of hydroxylamine at high concentration with deoxycytidine or with polycytidylic acid: Evidence that substitution of amino groups in cytosine residues by hydroxylamino is a primary reaction, and the possible relevance to hydroxylamine mutagenesisJournal of Molecular Biology, 1967