1rnl
From Proteopedia
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THE NITRATE/NITRITE RESPONSE REGULATOR PROTEIN NARL FROM NARL
Overview
The crystal structure analysis of the NarL protein provides a first look, at interactions between receiver and effector domains of a full-length, bacterial response regulator. The N-terminal receiver domain, with 131, amino acids, is folded into a 5-strand beta sheet flanked by 5 alpha, helices, as seen in CheY and in the N-terminal domain of NTRC. The, C-terminal DNA-binding domain, with 62 amino acids, is a compact bundle of, 4 alpha helices, of which the middle 2 form a helix-turn-helix motif, closely related to that of Drosophila paired protein and other H-T-H, DNA-binding proteins. The 2 domains are connected by an alpha helix of 10, amino acids and a 13-residue flexible tether that is not visible and, presumably disordered in the X-ray structure. In this unphosphorylated, form of NarL, the C-terminal domain is turned against the receiver domain, in a manner that would preclude DNA binding. Activation of NarL via, phosphorylation of Asp59 must involve transfer of information to the, interdomain interface and either rotation or displacement of the, DNA-binding C-terminal domain. Docking of a B-DNA duplex against the, isolated C-terminal domain in the manner observed in paired protein and, other H-T-H proteins suggests a stereochemical basis for DNA sequence, preference: T-R-C-C-Y (high affinity) or T-R-C-T-N (low affinity), which, is close to the experimentally observed consensus sequence: T-A-C-Y-N. The, NarL structure is a model for other members of the FixJ or LuxR family of, bacterial transcriptional activators, and possibly to the more distant, OmpR and NtrC families as well.
About this Structure
1RNL is a Single protein structure of sequence from Escherichia coli with PT and GOL as ligands. Structure known Active Site: 1. Full crystallographic information is available from OCA.
Reference
Structure of the Escherichia coli response regulator NarL., Baikalov I, Schroder I, Kaczor-Grzeskowiak M, Grzeskowiak K, Gunsalus RP, Dickerson RE, Biochemistry. 1996 Aug 27;35(34):11053-61. PMID:8780507
Page seeded by OCA on Mon Nov 5 13:18:04 2007
