2h6c: Difference between revisions

Revision as of 18:38, 21 February 2008

Crystal structure of reduced CprK in absence of any ligand

OverviewOverview

Halorespiration is a bacterial respiratory process in which haloorganic compounds act as terminal electron acceptors. This process is controlled at transcriptional level by CprK, a member of the ubiquitous CRP-FNR family. Here we present the crystal structures of oxidized CprK in presence of the ligand ortho-chlorophenolacetic acid and of reduced CprK in absence of this ligand. These structures reveal that highly specific binding of chlorinated, rather than the corresponding non-chlorinated, phenolic compounds in the NH(2)-terminal beta-barrels causes reorientation of these domains with respect to the central alpha-helix at the dimer interface. Unexpectedly, the COOH-terminal DNA-binding domains dimerize in the non-DNA binding state. We postulate the ligand-induced conformational change allows formation of interdomain contacts that disrupt the DNA domain dimer interface and leads to repositioning of the helix-turn-helix motifs. These structures provide a structural framework for further studies on transcriptional control by CRP-FNR homologs in general and of halorespiration regulation by CprK in particular.

About this StructureAbout this Structure

2H6C is a Protein complex structure of sequences from Desulfitobacterium dehalogenans. Full crystallographic information is available from OCA.

ReferenceReference

CprK crystal structures reveal mechanism for transcriptional control of halorespiration., Joyce MG, Levy C, Gabor K, Pop SM, Biehl BD, Doukov TI, Ryter JM, Mazon H, Smidt H, van den Heuvel RH, Ragsdale SW, van der Oost J, Leys D, J Biol Chem. 2006 Sep 22;281(38):28318-25. Epub 2006 Jun 27. PMID:16803881

Page seeded by OCA on Thu Feb 21 17:38:35 2008

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 ==Overview==
-Halorespiration is a bacterial respiratory process in which haloorganic, compounds act as terminal electron acceptors. This process is controlled, at transcriptional level by CprK, a member of the ubiquitous CRP-FNR, family. Here we present the crystal structures of oxidized CprK in, presence of the ligand ortho-chlorophenolacetic acid and of reduced CprK, in absence of this ligand. These structures reveal that highly specific, binding of chlorinated, rather than the corresponding non-chlorinated, phenolic compounds in the NH(2)-terminal beta-barrels causes reorientation, of these domains with respect to the central alpha-helix at the dimer, interface. Unexpectedly, the COOH-terminal DNA-binding domains dimerize in, the non-DNA binding state. We postulate the ligand-induced conformational, change allows formation of interdomain contacts that disrupt the DNA, domain dimer interface and leads to repositioning of the helix-turn-helix, motifs. These structures provide a structural framework for further, studies on transcriptional control by CRP-FNR homologs in general and of, halorespiration regulation by CprK in particular.
+Halorespiration is a bacterial respiratory process in which haloorganic compounds act as terminal electron acceptors. This process is controlled at transcriptional level by CprK, a member of the ubiquitous CRP-FNR family. Here we present the crystal structures of oxidized CprK in presence of the ligand ortho-chlorophenolacetic acid and of reduced CprK in absence of this ligand. These structures reveal that highly specific binding of chlorinated, rather than the corresponding non-chlorinated, phenolic compounds in the NH(2)-terminal beta-barrels causes reorientation of these domains with respect to the central alpha-helix at the dimer interface. Unexpectedly, the COOH-terminal DNA-binding domains dimerize in the non-DNA binding state. We postulate the ligand-induced conformational change allows formation of interdomain contacts that disrupt the DNA domain dimer interface and leads to repositioning of the helix-turn-helix motifs. These structures provide a structural framework for further studies on transcriptional control by CRP-FNR homologs in general and of halorespiration regulation by CprK in particular.
 ==About this Structure==
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 [[Category: helix-turn-helix]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 20:15:18 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:38:35 2008''