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The Sugar Porin (SP) Family [Function: Specific channels] Seed alignment | Full alignment in OMPdb | |
This family includes the well characterized maltoporins of Escherichia coli and Salmonella typhimurium as well as the sucrose-specific porin of Salmonella typhimurium, whose 3D structures have been resolved by X-ray diffraction. These porins form trimers but, in contrast to proteins belonging to other bacterial porin families which consist of 16 beta-stranded ß-barrels, they consist of an 18 beta-stranded ß-barrel. Despite the wider barrel compared to other porins, sugar-specific porins exhibit a narrower channel, showing only a small fraction of the ionic conductance of the latter porins. There is also evidence that in most cases, the N-terminal residues form a coiled-coil of alpha helices facilitating low-affinity sugar binding and supramolecular stabilisation. | |
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Literature references | |
Structure and functional characterization of the periplasmic N-terminal polypeptide domain of the sugar-specific ion channel protein (ScrY porin) Protein Sci. 2002 Jun;11(6):1565-74. doi: 10.1110/ps.2760102. PMID: 12021455 | |
Crystallization and preliminary X-ray diffraction analysis of ScrY, a specific bacterial outer membrane porin J Mol Biol. 1993 Jan 5;229(1):258-62. doi: 10.1006/jmbi.1993.1028. PMID: 8421311 | |
Structural basis for sugar translocation through maltoporin channels at 3.1 A resolution Science. 1995 Jan 27;267(5197):512-4. doi: 10.1126/science.7824948. PMID: 7824948 | |
Channel specificity: structural basis for sugar discrimination and differential flux rates in maltoporin J Mol Biol. 1997 Sep 12;272(1):56-63. doi: 10.1006/jmbi.1997.1224. PMID: 9299337 | |
Structure of the sucrose-specific porin ScrY from Salmonella typhimurium and its complex with sucrose Nat Struct Biol. 1998 Jan;5(1):37-46. doi: 10.1038/nsb0198-37. PMID: 9437428 | |
Structure of maltoporin from Salmonella typhimurium ligated with a nitrophenyl-maltotrioside J Mol Biol. 1997 Mar 7;266(4):761-75. doi: 10.1006/jmbi.1996.0823. PMID: 9102468 | |
Proteins in this family with 3D-structure | |
P02943 | |
P26466 | |
P22340 |
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