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NMR studies of the hydrogen bonds involving the catalytic triad of Escherichia coli thioesterase/protease I
Author(s) -
Tyukhtenko Sergiy I,
Litvinchuk Alexandra V,
Chang Chi-Fon,
Leu Ruey-Jyh,
Shaw Jei-Fu,
Huang Tai-Huang
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03308-2
Subject(s) - catalytic triad , chemistry , hydrogen bond , escherichia coli , thioesterase , stereochemistry , residue (chemistry) , catalysis , protease , enzyme , triad (sociology) , serine , crystallography , molecule , biochemistry , biosynthesis , organic chemistry , gene , psychology , psychoanalysis
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 δ1 H, Ser 10 ‐O γ H and His 157 ‐N ϵ2 H, respectively. Thus, the presence of a strong Asp 154 –His 157 hydrogen bond in free TEP‐I was observed. However, Ser 10 ‐O γ H was shown to form a H‐bond with a residue other than His 157 ‐N ϵ2 .