NMR studies of the hydrogen bonds involving the catalytic triad of Escherichia coli thioesterase/protease I.
Escherichia coli thioesterase/protease I (TEP-I) is a lipolytic enzyme of the serine protease superfamily with Ser(10), Asp(154) and His(157) as the catalytic triad residues. Based on comparison of the low-field (1)H nuclear magnetic resonance spectra of two mutants (S10G and S12G) and two transition state analogue complexes we have assigned the exchangeable proton resonances at 16.3 ppm, 14.3 ppm, and 12.8 ppm at pH 3.5 to His(157)-N(delta1)H, Ser(10)-O(gamma)H and His(157)-N(epsilon2)H, respectively. Thus, the presence of a strong Asp(154)-His(157) hydrogen bond in free TEP-I was observed. However, Ser(10)-O(gamma)H was shown to form a H-bond with a residue other than His(157)-N(epsilon2).
Tyukhtenko
Sergiy I
SI
Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan ROC.
Litvinchuk
Alexandra V
AV
Chang
Chi-Fon
CF
Leu
Ruey-Jyh
RJ
Shaw
Jei-Fu
JF
Huang
Tai-Huang
TH
D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D008245:Lysophospholipase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D033903:Periplasmic Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D011522:Protons; D012694:Serine / Q000737:chemistry
D029968:Escherichia coli Proteins; D033903:Periplasmic Proteins; D011522:Protons; D012694:Serine; D008245:Lysophospholipase; C400724:tesA protein, E coli