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1n4d

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Revision as of 10:23, 25 October 2017

The Ligand-Free Structure of E coli BtuF, the Periplasmic Binding Protein for Vitamin B12

Structural highlights

1n4d is a 2 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
NonStd Res:
Related:	1n4a
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[BTUF_ECOLI] Part of the ABC transporter complex BtuCDF involved in vitamin B12 import. Binds vitamin B12 and delivers it to the periplasmic surface of BtuC.^[1]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

BtuF is the periplasmic binding protein (PBP) for the vitamin B12 transporter BtuCD, a member of the ATP-binding cassette (ABC) transporter superfamily of transmembrane pumps. We have determined crystal structures of Escherichia coli BtuF in the apo state at 3.0 A resolution and with vitamin B12 bound at 2.0 A resolution. The structure of BtuF is similar to that of the FhuD and TroA PBPs and is composed of two alpha/beta domains linked by a rigid alpha-helix. B12 is bound in the "base-on" or vitamin conformation in a wide acidic cleft located between these domains. The C-terminal domain shares structural homology to a B12-binding domain found in a variety of enzymes. The same surface of this domain interacts with opposite surfaces of B12 when comparing ligand-bound structures of BtuF and the homologous enzymes, a change that is probably caused by the obstruction of the face that typically interacts with this domain by the base-on conformation of vitamin B12 bound to BtuF. There is no apparent pseudo-symmetry in the surface properties of the BtuF domains flanking its B12 binding site even though the presumed transport site in the previously reported crystal structure of BtuCD is located in an intersubunit interface with 2-fold symmetry. Unwinding of an alpha-helix in the C-terminal domain of BtuF appears to be part of conformational change involving a general increase in the mobility of this domain in the apo structure compared with the B12-bound structure. As this helix is located on the surface likely to interact with BtuC, unwinding of the helix upon binding to BtuC could play a role in triggering release of B12 into the transport cavity. Furthermore, the high mobility of this domain in free BtuF could provide an entropic driving force for the subsequent release of BtuF required to complete the transport cycle.

Crystal structures of the BtuF periplasmic-binding protein for vitamin B12 suggest a functionally important reduction in protein mobility upon ligand binding.,Karpowich NK, Huang HH, Smith PC, Hunt JF J Biol Chem. 2003 Mar 7;278(10):8429-34. Epub 2002 Dec 4. PMID:12468528^[2]

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

References

↑ Cadieux N, Bradbeer C, Reeger-Schneider E, Koster W, Mohanty AK, Wiener MC, Kadner RJ. Identification of the periplasmic cobalamin-binding protein BtuF of Escherichia coli. J Bacteriol. 2002 Feb;184(3):706-17. PMID:11790740
↑ Karpowich NK, Huang HH, Smith PC, Hunt JF. Crystal structures of the BtuF periplasmic-binding protein for vitamin B12 suggest a functionally important reduction in protein mobility upon ligand binding. J Biol Chem. 2003 Mar 7;278(10):8429-34. Epub 2002 Dec 4. PMID:12468528 doi:10.1074/jbc.M212239200

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1n4d"

@@ Line 1: / Line 1: @@
 ==The Ligand-Free Structure of E coli BtuF, the Periplasmic Binding Protein for Vitamin B12==
 <StructureSection load='1n4d' size='340' side='right' caption='[[1n4d]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
@@ Line 5: / Line 6: @@
 </td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr>
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1n4a|1n4a]]</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=1n4d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n4d OCA], [http://pdbe.org/1n4d PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1n4d RCSB], [http://www.ebi.ac.uk/pdbsum/1n4d 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=1n4d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n4d OCA], [http://pdbe.org/1n4d PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1n4d RCSB], [http://www.ebi.ac.uk/pdbsum/1n4d PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1n4d ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 17: / Line 18: @@
     <text>to colour the structure by Evolutionary Conservation</text>
   </jmolCheckbox>
-</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1n4d ConSurf].
 <div style="clear:both"></div>
 <div style="background-color:#fffaf0;">

1n4d

From Proteopedia

Revision as of 10:23, 25 October 2017

The Ligand-Free Structure of E coli BtuF, the Periplasmic Binding Protein for Vitamin B12

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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