Secondary literature sources for HPT

The following references were automatically generated.

Cheung J, Le-Khac M, Hendrickson WA
Crystal structure of a histidine kinase sensor domain with similarity toperiplasmic binding proteins.
Proteins. 2009; 77: 235-41

Wang S, Engohang-Ndong J, Smith I
Structure of the DNA-binding domain of the response regulator PhoP fromMycobacterium tuberculosis.
Biochemistry. 2007; 46: 14751-61
Display abstract
The PhoP-PhoR two-component signaling system from Mycobacteriumtuberculosis is essential for the virulence of the tubercle bacillus. Theresponse regulator, PhoP, regulates expression of over 110 genes. In orderto elucidate the regulatory mechanism of PhoP, we determined the crystalstructure of its DNA-binding domain (PhoPC). PhoPC exhibits a typical foldof the winged helix-turn-helix subfamily of response regulators. Thestructure starts with a four-stranded antiparallel beta-sheet, followed bya three-helical bundle of alpha-helices, and then a C-terminalbeta-hairpin, which together with a short beta-strand between the firstand second helices forms a three-stranded antiparallel beta-sheet.Structural elements are packed through a hydrophobic core, with the firsthelix providing a scaffold for the rest of the domain to pack. The secondand third helices and the long, flexible loop between them form thehelix-turn-helix motif, with the third helix being the recognition helix.The C-terminal beta-hairpin turn forms the wing motif. The molecularsurfaces around the recognition helix and the wing residues show strongpositive electrostatic potential, consistent with their roles in DNAbinding and nucleotide sequence recognition. The crystal packing of PhoPCgives a hexamer ring, with neighboring molecules interacting in ahead-to-tail fashion. This packing interface suggests that PhoPC couldbind DNA in a tandem association. However, this mode of DNA binding islikely to be nonspecific because the recognition helix is partiallyblocked and would be prevented from inserting into the major groove ofDNA. Detailed structural analysis and implications with respect to DNAbinding are discussed.

Hamada K, Kato M, Shimizu T, Ihara K, Mizuno T, Hakoshima T
Crystal structure of the protein histidine phosphatase SixA in themultistep His-Asp phosphorelay.
Genes Cells. 2005; 10: 1-11
Display abstract
The multiple histidine-aspartate phosphorelay system plays a crucial rolein cellular adaptation to environments in microorganisms and plants. Likekinase-phosphatase systems in higher eukaryotes, the multiple stepsprovide additional regulatory checkpoints with phosphatases. TheEscherichia coli phosphatase SixA exhibits protein phosphatase activityagainst the histidine-containing phosphotransfer (HPt) domain located inthe C-terminus of the histidine kinase ArcB engaged in anaerobicresponses. We have determined the crystal structures of the free andtungstate-bound forms of SixA at 2.06 A and 1.90 A resolution,respectively. The results provide the first three-dimensional view of abacterial protein histidine phosphatase, revealing a compact alpha/betaarchitecture related to a family of phosphatases containing thearginine-histidine-glycine (RHG) motif at their active sites. Comparedwith these RHG phosphatases, SixA lacks an extra alpha-helical subdomainas a lid over the active site, thereby forming a relatively shallow grooveimportant for the accommodation of the HPt domain of ArcB. The tungstateion, which mimics the substrate phosphate group, is located at the centreof the active site where the active residue, His8, points to the tungstenatom in the mode of in-line nucleophilic attack.

Wang L et al.
Dissection of the functional and structural domains of phosphorelayhistidine kinase A of Bacillus subtilis.
J Bacteriol. 2001; 183: 2795-802
Display abstract
The initiation of sporulation in Bacillus subtilis results primarily fromphosphoryl group input into the phosphorelay by histidine kinases, themajor kinase being kinase A. Kinase A is active as a homodimer, theprotomer of which consists of an approximately 400-amino-acid N-terminalputative signal-sensing region and a 200-amino-acid C-terminal autokinase.On the basis of sequence similarity, the N-terminal region may besubdivided into three PAS domains: A, B, and C, located from the N- to theC-terminal end. Proteolysis experiments and two-hybrid analyses indicatedthat dimerization of the N-terminal region is accomplished through thePAS-B/PAS-C region of the molecule, whereas the most amino-proximal PAS-Adomain is not dimerized. N-terminal deletions generated with maltosebinding fusion proteins showed that an intact PAS-A domain is veryimportant for enzymatic activity. Amino acid substitution mutations inPAS-A as well as PAS-C affected the in vivo activity of kinase A,suggesting that both PAS domains are required for signal sensing. TheC-terminal autokinase, when produced without the N-terminal region, was adimer, probably because of the dimerization required for formation of thefour-helix-bundle phosphotransferase domain. The truncated autokinase wasvirtually inactive in autophosphorylation with ATP, whereasphosphorylation of the histidine of the phosphotransfer domain by backreactions from Spo0F~P appeared normal. The phosphorylated autokinase lostthe ability to transfer its phosphoryl group to ADP, however. TheN-terminal region appears to be essential both for signal sensing and formaintaining the correct conformation of the autokinase component domains.

Matsushika A, Mizuno T
Characterization of three putative sub-domains in the signal-input domainof the ArcB hybrid sensor in Escherichia coli(1).
J Biochem. 2000; 127: 855-60
Display abstract
The ArcB sensor plays a crucial role in the histidine to aspartate(His-to-Asp) phosphorelay signal transduction, which is involved in thetranscriptional regulatory network that allows Escherichia coli cells tosense various respiratory growth conditions. ArcB is one of thebest-studied hybrid His-kinases involved in the multi-step His-to-Aspphosphorelay. However, a major question that remains to be elucidated is:how does ArcB sense an anoxic signal? The N-terminal region of ArcB isconsidered to be a signal-input domain, which probably plays a role insuch signal-perception. In this study, this N-terminal region of ArcB wasdissected into three putative sub-domains, a "transmembrane domain," a"leucine-zipper-like domain, " and a "PAS-like domain." The importance ofthese structural domains was assessed in vivo and in vitro bysystematically analyzing a number of arcB mutants, each of which encodes amutant ArcB protein having an amino acid substitution or a deletion withinone of these sub-domains. The results are discussed with special referenceto the nature of the ArcB anaerobic sensor.

Misra S, Beach BM, Hurley JH
Structure of the VHS domain of human Tom1 (target of myb 1): insights intointeractions with proteins and membranes.
Biochemistry. 2000; 39: 11282-90
Display abstract
VHS domains are found at the N-termini of select proteins involved inintracellular membrane trafficking. We have determined the crystalstructure of the VHS domain of the human Tom1 (target of myb 1) protein to1.5 A resolution. The domain consists of eight helices arranged in asuperhelix. The surface of the domain has two main features: (1) a basicpatch on one side due to several conserved positively charged residues onhelix 3 and (2) a negatively charged ridge on the opposite side, formed byresidues on helix 2. We compare our structure to the recently obtainedstructure of tandem VHS-FYVE domains from Hrs [Mao, Y., Nickitenko, A.,Duan, X., Lloyd, T. E., Wu, M. N., Bellen, H., and Quiocho, F. A. (2000)Cell 100, 447-456]. Key features of the interaction surface between theFYVE and VHS domains of Hrs, involving helices 2 and 4 of the VHS domain,are conserved in the VHS domain of Tom1, even though Tom1 does not have aFYVE domain. We also compare the structures of the VHS domains of Tom1 andHrs to the recently obtained structure of the ENTH domain of epsin-1[Hyman, J., Chen, H., Di Fiore, P. P., De Camilli, P., and Brunger, A. T.(2000) J. Cell Biol. 149, 537-546]. Comparison of the two VHS domains andthe ENTH domain reveals a conserved surface, composed of helices 2 and 4,that is utilized for protein-protein interactions. In addition, VHSdomain-containing proteins are often localized to membranes. We suggestthat the conserved positively charged surface of helix 3 in VHS and ENTHdomains plays a role in membrane binding.

Kato M, Mizuno T, Shimizu T, Hakoshima T
Insights into multistep phosphorelay from the crystal structure of theC-terminal HPt domain of ArcB.
Cell. 1997; 88: 717-23
Display abstract
The histidine-containing phosphotransfer (HPt) domain is a novel proteinmodule with an active histidine residue that mediates phosphotransferreactions in the two-component signaling systems. A multistep phosphorelayinvolving the HPt domain has been suggested for these signaling pathways.The crystal structure of the HPt domain of the anaerobic sensor kinaseArcB has been determined at 2.06 A resolution. The domain consists of sixalpha helices containing a four-helix bundle-folding. The pattern ofsequence similarity of the HPt domains of ArcB and components in othersignaling systems can be interpreted in light of the three-dimensionalstructure and supports the conclusion that the HPt domains have a commonstructural motif both in prokaryotes and eukaryotes.