XB-ART-45416
Biochemistry
2012 Apr 17;5115:3284-91. doi: 10.1021/bi201934h.
Show Gene links
Show Anatomy links
Functionally important amino acids in rice sucrose transporter OsSUT1.
???displayArticle.abstract???
Six conserved, charged amino acids within membrane spans in rice sucrose transporter OsSUT1 were identified using a three-dimensional structural model based on the crystal structures of three major facilitator superfamily (MFS) proteins: LacY, GlpT, and EmrD. These positions in OsSUT1 were selected for mutagenesis and biochemical assays. Among the six mutants, D177N completely lost transport function, D331N retained only a small fraction of sucrose uptake activity (2.3% of that of the wild type), and R335H and E336Q also displayed a substantial decrease in transport activity. D329N functioned as well as wild-type OsSUT1. R188K did not transport sucrose but showed a H(+) leak that was inhibited by sucrose, indicating that R188K had uncoupled sucrose and H(+) translocation. This demonstrates that charged amino acids within membrane spans are important for the transport mechanism of OsSUT1 as they are in lactose permease.
???displayArticle.pubmedLink??? 22458969
???displayArticle.link??? Biochemistry