Diallinas G. Transporter Specificity: A Tale of Loosened Elevator-Sliding.
Trends Biochem Sci 2021;
46:708-717. [PMID:
33903007 DOI:
10.1016/j.tibs.2021.03.007]
[Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/13/2021] [Accepted: 03/26/2021] [Indexed: 12/14/2022]
Abstract
Elevator-type transporters are a group of proteins translocating nutrients and metabolites across cell membranes. Despite structural and functional differences, elevator-type transporters use a common mechanism of substrate translocation via reversible movements of a mobile core domain (the elevator), which includes the substrate binding site, along a rigid scaffold domain, stably anchored in the plasma membrane. How substrate specificity is determined in elevator transporters remains elusive. Here, I discuss how a recent report on the sliding elevator mechanism, seen under the context of genetic analysis of a prototype fungal transporter, sheds light on how specificity might be genetically modified. I propose that flexible specificity alterations might occur by 'loosening' of the sliding mechanism from tight coupling to substrate binding.
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