4m64

<StructureSection load='4m64' size='340' side='right' caption='[[4m64]], [[Resolution|resolution]] 3.35&Aring;' scene=''>

<table><tr><td colspan='2'>[[4m64]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Salty Salty]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4M64 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4M64 FirstGlance]. <br>

</td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">melB, STM4299 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=99287 SALTY])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4m64 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4m64 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4m64 RCSB], [http://www.ebi.ac.uk/pdbsum/4m64 PDBsum]</span></td></tr>

== Publication Abstract from PubMed ==

The bacterial melibiose permease (MelB) belongs to the glycoside-pentoside-hexuronide:cation symporter family, a part of the major facilitator superfamily (MFS). Structural information regarding glycoside-pentoside-hexuronide:cation symporter family transporters and other Na(+)-coupled permeases within MFS has been lacking, although a wealth of biochemical and biophysical data are available. Here we present the three-dimensional crystal structures of Salmonella typhimurium MelBSt in two conformations, representing an outward partially occluded and an outward inactive state of MelBSt. MelB adopts a typical MFS fold and contains a previously unidentified cation-binding motif. Three conserved acidic residues form a pyramidal-shaped cation-binding site for Na(+), Li(+) or H(+), which is in close proximity to the sugar-binding site. Both cosubstrate-binding sites are mainly contributed by the residues from the amino-terminal domain. These two structures and the functional data presented here provide mechanistic insights into Na(+)/melibiose symport. We also postulate a structural foundation for the conformational cycling necessary for transport catalysed by MFS permeases in general.

 

Structure-based mechanism for Na(+)/melibiose symport by MelB.,Ethayathulla AS, Yousef MS, Amin A, Leblanc G, Kaback HR, Guan L Nat Commun. 2014 Jan 6;5:3009. doi: 10.1038/ncomms4009. PMID:24389923<ref>PMID:24389923</ref>

== References ==

[[Category: Salty]]

[[Category: Ethayathulla, A S]]

[[Category: Guan, L]]

[[Category: Glycoside-pentoside-hexuronide:cation symporter family]]

[[Category: Transport protein]]