1r62
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(New page: 200px<br /><applet load="1r62" size="450" color="white" frame="true" align="right" spinBox="true" caption="1r62, resolution 1.60Å" /> '''Crystal structure of...)
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Revision as of 23:10, 20 November 2007
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Crystal structure of the C-terminal Domain of the Two-Component System Transmitter Protein NRII (NtrB)
Overview
The kinase/phosphatase nitrogen regulator II (NRII, NtrB) is a member of, the transmitter protein family of conserved two-component signal, transduction systems. The kinase activity of NRII brings about the, phosphorylation of the transcription factor nitrogen regulator I (NRI, NtrC), causing the activation of Ntr gene transcription. The phosphatase, activity of NRII results in the inactivation of NRI-P. The activities of, NRII are regulated by the signal transduction protein encoded by glnB, PII, protein, which upon binding to NRII inhibits the kinase and activates the, phosphatase activity. The C-terminal ATP-binding domain of NRII is, required for both the kinase and phosphatase activities and contains the, PII binding site. Here, we present the crystal structure of the C-terminal, domain of a mutant form of NRII, NRII-Y302N, at 1.6 A resolution and, compare this structure to the analogous domains of other two-component, system transmitter proteins. While the C-terminal domain of NRII shares, the general tertiary structure seen in CheA, PhoQ, and EnvZ transmitter, proteins, it contains a distinct beta-hairpin projection that is absent in, these related proteins. This projection is near the site of a, well-characterized mutation that reduces the binding of PII and near other, less-characterized mutations that affect the phosphatase activity of NRII., Sequence alignment suggests that the beta-hairpin projection is present in, NRII proteins from various organisms, and absent in other transmitter, proteins from Escherichia coliK-12. This unique structural element in the, NRII C-terminal domain may play a role in binding PII or in intramolecular, signal transduction.
About this Structure
1R62 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystal structure of the C-terminal domain of the two-component system transmitter protein nitrogen regulator II (NRII; NtrB), regulator of nitrogen assimilation in Escherichia coli., Song Y, Peisach D, Pioszak AA, Xu Z, Ninfa AJ, Biochemistry. 2004 Jun 1;43(21):6670-8. PMID:15157101
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