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3ooa

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Revision as of 12:00, 4 August 2016

Crystal structures and biochemical characterization of the bacterial solute receptor AcbH reveal an unprecedented exclusive substrate preference for b-D-galactopyranose

Structural highlights

3ooa is a 2 chain structure with sequence from Acts5. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Related:	3oo6, 3oo7, 3oo8, 3oo9
Gene:	AcbH (ACTS5)
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Publication Abstract from PubMed

Solute receptors (binding proteins) are indispensable components of canonical ATP-binding cassette importers in prokaryotes. Here, we report on the characterization and crystal structures in the closed and open conformations of AcbH, the solute receptor of the putative carbohydrate transporter AcbFG which is encoded in the acarbose (acarviosyl-1,4-maltose) biosynthetic gene cluster from Actinoplanes sp. SE50/110. Binding assays identified AcbH as a high-affinity monosaccharide-binding protein with a dissociation constant (K(d)) for beta-d-galactopyranose of 9.8+/-1.0 nM. Neither galactose-containing di- and trisaccharides, such as lactose and raffinose, nor monosaccharides including d-galacturonic acid, l-arabinose, d-xylose and l-rhamnose competed with [(1)(4)C]galactose for binding to AcbH. Moreover, AcbH does not bind d-glucose, which is a common property of all but one d-galactose-binding proteins characterized to date. Strikingly, determination of the X-ray structure revealed that AcbH is structurally homologous to maltose-binding proteins rather than to glucose-binding proteins. Two helices are inserted in the substrate-binding pocket, which reduces the cavity size and allows the exclusive binding of monosaccharides, specifically beta-d-galactopyranose, in the (4)C(1) conformation. Site-directed mutagenesis of three residues from the binding pocket (Arg82, Asp361 and Arg362) that interact with the axially oriented O4-H hydroxyl of the bound galactopyranose and subsequent functional analysis indicated that these residues are crucial for galactose binding. To our knowledge, this is the first report of the tertiary structure of a solute receptor with exclusive affinity for beta-d-galactopyranose. The putative role of a galactose import system in the context of acarbose metabolism in Actinoplanes sp. is discussed.

Crystal structures of the bacterial solute receptor AcbH displaying an exclusive substrate preference for beta-D-galactopyranose.,Licht A, Bulut H, Scheffel F, Daumke O, Wehmeier UF, Saenger W, Schneider E, Vahedi-Faridi A J Mol Biol. 2011 Feb 11;406(1):92-105. Epub 2010 Dec 17. PMID:21168419^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Licht A, Bulut H, Scheffel F, Daumke O, Wehmeier UF, Saenger W, Schneider E, Vahedi-Faridi A. Crystal structures of the bacterial solute receptor AcbH displaying an exclusive substrate preference for beta-D-galactopyranose. J Mol Biol. 2011 Feb 11;406(1):92-105. Epub 2010 Dec 17. PMID:21168419 doi:http://dx.doi.org/10.1016/j.jmb.2010.11.048

1 Structural highlights
2 Publication Abstract from PubMed
3 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3ooa"

@@ Line 1: / Line 1: @@
 ==Crystal structures and biochemical characterization of the bacterial solute receptor AcbH reveal an unprecedented exclusive substrate preference for b-D-galactopyranose==
 <StructureSection load='3ooa' size='340' side='right' caption='[[3ooa]], [[Resolution|resolution]] 2.04&Aring;' scene=''>
@@ Line 6: / Line 7: @@
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3oo6|3oo6]], [[3oo7|3oo7]], [[3oo8|3oo8]], [[3oo9|3oo9]]</td></tr>
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">AcbH ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=134676 ACTS5])</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=3ooa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ooa OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3ooa RCSB], [http://www.ebi.ac.uk/pdbsum/3ooa PDBsum]</span></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=3ooa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ooa OCA], [http://pdbe.org/3ooa PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3ooa RCSB], [http://www.ebi.ac.uk/pdbsum/3ooa PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3ooa ProSAT]</span></td></tr>
 </table>
 <div style="background-color:#fffaf0;">
@@ Line 16: / Line 17: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 3ooa" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

3ooa

From Proteopedia

Revision as of 12:00, 4 August 2016

Crystal structures and biochemical characterization of the bacterial solute receptor AcbH reveal an unprecedented exclusive substrate preference for b-D-galactopyranose

Structural highlights

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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