3ga5
From Proteopedia
X-ray structure of glucose/galactose receptor from Salmonella typhimurium in complex with (2R)-glyceryl-beta-D-galactopyranoside
Structural highlights
FunctionMGLB_SALTY Part of the ABC transporter complex MglABC involved in galactose/methyl galactoside import (By similarity). In addition, binds D-galactose and D-glucose and plays a role in the chemotaxis towards these two sugars by interacting with the Trg chemoreceptor (Probable).[UniProtKB:P0AEE5][1] [2] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPeriplasmic binding proteins are abundant in bacteria by virtue of their essential roles as high-affinity receptors in ABC transport systems and chemotaxis. One of the best studied of these receptors is the so-called glucose/galactose-binding protein. Here, we report the X-ray structure of the Salmonella typhimurium protein bound to the physiologically relevant ligand, (2R)-glyceryl-beta-D-galactopyranoside, solved by molecular replacement, and refined to 1.87 A resolution with R and R-free values of 17% and 22%. The structure identifies three amino acid residues that are diagnostic of (2R)-glyceryl-beta-D-galactopyranoside binding (Thr110, Asp154 and Gln261), as opposed to binding to the monosaccharides glucose and galactose. These three residues are conserved in essentially all available glucose/galactose-binding protein sequences, indicating that the binding of (2R)-glyceryl-beta-D-galactopyranoside is the rule rather than the exception for receptors of this type. The role of (2R)-glyceryl-beta-D-galactopyranoside in bacterial biology is discussed. Further, comparison of the available structures provides the most complete description of the conformational changes of glucose/galactose-binding protein to date. The structures follow a smooth and continuous path from the most closed structure [that bound to (2R)-glyceryl-beta-D-galactopyranoside] to the most open (an apo structure). X-ray structure of glucose/galactose receptor from Salmonella typhimurium in complex with the physiological ligand, (2R)-glyceryl-beta-D-galactopyranoside.,Sooriyaarachchi S, Ubhayasekera W, Boos W, Mowbray SL FEBS J. 2009 Apr;276(7):2116-24. PMID:19292879[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|