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Characterization of the Phytophthora sojae hypotaurocyamine kinase suggests early evolution of quaternary structure in the phosphagen kinase family
Author(s) -
Van Houten Jason Michael,
Palmer Allyson,
Herring Kelsie,
Snider Mark J,
Fraga Dean
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.928.14
Subject(s) - isothermal titration calorimetry , arginine kinase , substrate (aquarium) , reactivity (psychology) , creatine kinase , biochemistry , loop mediated isothermal amplification , arginine , chemistry , kinase , biology , microbiology and biotechnology , amino acid , medicine , dna , ecology , alternative medicine , pathology
We investigated the substrate specificity and kinetic constants of a Phytophthora sojae hypotaurocyamine kinase (HTK) to better understand the evolution of the phosphagen kinase (PK) protein family. The substrate specificity and kinetic constants were determined using Isothermal Titration Calorimetry by titrating arginine, creatine, glycocyamine, or taurocyamine at varying concentrations in to a solution containing the HTK and MgATP. The protein had strong reactivity with taurocyamine and weak reactivity with glycocyamine, while it showed no reactivity with either arginine or creatine. The K m for taurocyamine and MgATP were found to be 0.59mM and 3.78mM respectively. The k cat was found to be 34.66s −1 . Based on our phylogenetic analysis and the ability for the P. sojae HTK to react with glycocyamine, we hypothesized that the dimeric PKs evolved from an ancestral kinase that may have had some promiscuity in substrate specificity. Using protein sequences of known dimeric PKs, we tested this hypothesis by constructing ancestral sequences using the web‐based program ANCESCON. This project was made possible by the support of the Howard Hughes Medical Institute and the Henry J. Copeland Fund.