2vlg

KINA PAS-A DOMAIN, HOMODIMER

spinqualitylabelsall models 2vlg, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2vlg is a 4 chain structure with sequence from Bacillus subtilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ACT, CL Activity: Histidine kinase, with EC number 2.7.13.3 Resources: FirstGlance, OCA, RCSB, PDBsum 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 The Bacillus subtilis KinA protein is a histidine protein kinase that controls the commitment of this organism to sporulate in response to nutrient deprivation and several other conditions. Prior studies indicated that the N-terminal Per-ARNT-Sim domain (PAS-A) plays a critical role in the catalytic activity of this enzyme, as demonstrated by the significant decrease of the autophosphorylation rate of a KinA protein lacking this domain. On the basis of the environmental sensing role played by PAS domains in a wide range of proteins, including other bacterial sensor kinases, it has been suggested that the PAS-A domain plays an important regulatory role in KinA function. We have investigated this potential by using a combination of biophysical and biochemical methods to examine PAS-A structure and function, both in isolation and within the intact protein. Here, we present the X-ray crystal structure of the KinA PAS-A domain, showing that it crystallizes as a homodimer using beta-sheet/beta-sheet packing interactions as observed for several other PAS domain complexes. Notably, we observed two dimers with tertiary and quaternary structure differences in the crystalline lattice, indicating significant structural flexibility in these domains. To confirm that KinA PAS-A also forms dimers in solution, we used a combination of NMR spectroscopy, gel filtration chromatography, and analytical ultracentrifugation, the results of which are all consistent with the crystallographic results. We experimentally tested the importance of several residues at the dimer interface using site-directed mutagenesis, finding changes in the PAS-A domain that significantly alter KinA enzymatic activity in vitro and in vivo. These results support the importance of PAS domains within KinA and other histidine kinases and suggest possible routes for natural or artificial regulation of kinase activity. Changes at the KinA PAS-A Dimerization Interface Influence Histidine Kinase Function(,).,Lee J, Tomchick DR, Brautigam CA, Machius M, Kort R, Hellingwerf KJ, Gardner KH Biochemistry. 2008 Mar 7;. PMID:18324779 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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