pH-profile crystal structure studies of C-terminal despentapeptide nitrite reductase from Achromobacter cycloclastes
Resource
Biochemical & Biophysical Research Communications 316, 107–113
Journal
Biochemical & Biophysical Research Communications 316, 107–113
Pages
-
Date Issued
2004-01-15
Date
2004-01-15
Author(s)
Li, Hai-Tao
Wang, Chao
Chang, Tschining
Chang, Wen-Chang
Liu, Ming-Yih
Gall, Jean Le
Gui, Lu-lu
Zhang, Ji-Ping
An, Xiao-Min
Chang, Wen-Rui
DOI
246246/2006111501265135
Abstract
Crystal structures of C-terminal despentapeptide nitrite reductase (NiRc-5) from Achromobacter cycloclastes were determined from 1.9 to 2.3A at pH 5.0, 5.4, & 6.2. NiRc-5, that has lost about 30% activity, is found to possess quite similar trimeric structures as the native enzyme. Electron density & copper content measurements indicate that the activity loss is not caused by the release of type 2 copper (T2Cu). pH-profile structural comparisons with native enzyme reveal that the T2Cu active center in NiRc-5 is perturbed, accounting for the partial loss of enzyme activity. This perturbation likely results from the less constrained conformations of two catalytic residues, Asp98 & His255. Hydrogen bonding analysis shows that the deletion of five residues causes a loss of more than half the intersubunit hydrogen bonds mediated by C-terminal tail. This study shows that the C-terminal tail plays an important role in controlling the conformations around the T2Cu site at the subunit interface, & helps keep the optimum microenvironment of active center for the full enzyme activity of AcNiR.
Crystal structures of C-terminal despentapeptide nitrite reductase (NiRc-5) from Achromobacter cycloclastes were determined
from 1.9 to 2.3A at pH 5.0, 5.4, and 6.2. NiRc-5, that has lost about 30% activity, is found to possess quite similar trimeric
structures as the native enzyme. Electron density and copper content measurements indicate that the activity loss is not caused by
the release of type 2 copper (T2Cu). pH-profile structural comparisons with native enzyme reveal that the T2Cu active center in
NiRc-5 is perturbed, accounting for the partial loss of enzyme activity. This perturbation likely results from the less constrained
conformations of two catalytic residues, Asp98 and His255. Hydrogen bonding analysis shows that the deletion of five residues
causes a loss of more than half the intersubunit hydrogen bonds mediated by C-terminal tail. This study shows that the C-terminal
tail plays an important role in controlling the conformations around the T2Cu site at the subunit interface, and helps keep the
optimum microenvironment of active center for the full enzyme activity of AcNiR.
Subjects
Crystal structure
Denitrification
Nitrite reductase
Residue deletion
pH profile
Achromobacter cycloclastes
SDGs
Publisher
Taipei:National Taiwan University Dept Chem Engn
Type
journal article
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