Research output: Contribution to journal › Article › peer-review
The role of active-site residues Phe98, HiS239, and Arg243 in DNA binding and in the catalysis of human uracil–DNA glycosylase SMUG1. / Iakovlev, Danila A.; Alekseeva, Irina V.; Vorobjev, Yury N. et al.
In: Molecules, Vol. 24, No. 17, 3133, 28.08.2019.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - The role of active-site residues Phe98, HiS239, and Arg243 in DNA binding and in the catalysis of human uracil–DNA glycosylase SMUG1
AU - Iakovlev, Danila A.
AU - Alekseeva, Irina V.
AU - Vorobjev, Yury N.
AU - Kuznetsov, Nikita A.
AU - Fedorova, Olga S.
PY - 2019/8/28
Y1 - 2019/8/28
N2 - Human SMUG1 (hSMUG1) hydrolyzes the N-glycosidic bond of uracil and some uracil lesions formed in the course of epigenetic regulation. Despite the functional importance of hSMUG1 in the DNA repair pathway, the damage recognition mechanism has been elusive to date. In the present study, our objective was to build a model structure of the enzyme–DNA complex of wild-type hSMUG1 and several hSMUG1 mutants containing substitution F98W, H239A, or R243A. Enzymatic activity of these mutant enzymes was examined by polyacrylamide gel electrophoresis analysis of the reaction product formation and pre-steady-state analysis of DNA conformational changes during enzyme–DNA complex formation. It was shown that substitutions F98W and H239A disrupt specific contacts generated by the respective wild-type residues, namely stacking with a flipped out Ura base in the damaged base-binding pocket or electrostatic interactions with DNA in cases of Phe98 and His239, respectively. A loss of the Arg side chain in the case of R243A reduced the rate of DNA bending and increased the enzyme turnover rate, indicating facilitation of the product release step.
AB - Human SMUG1 (hSMUG1) hydrolyzes the N-glycosidic bond of uracil and some uracil lesions formed in the course of epigenetic regulation. Despite the functional importance of hSMUG1 in the DNA repair pathway, the damage recognition mechanism has been elusive to date. In the present study, our objective was to build a model structure of the enzyme–DNA complex of wild-type hSMUG1 and several hSMUG1 mutants containing substitution F98W, H239A, or R243A. Enzymatic activity of these mutant enzymes was examined by polyacrylamide gel electrophoresis analysis of the reaction product formation and pre-steady-state analysis of DNA conformational changes during enzyme–DNA complex formation. It was shown that substitutions F98W and H239A disrupt specific contacts generated by the respective wild-type residues, namely stacking with a flipped out Ura base in the damaged base-binding pocket or electrostatic interactions with DNA in cases of Phe98 and His239, respectively. A loss of the Arg side chain in the case of R243A reduced the rate of DNA bending and increased the enzyme turnover rate, indicating facilitation of the product release step.
KW - DNA repair
KW - Fluorescence
KW - Homology modeling
KW - Human uracil–DNA glycosylase
KW - Molecular dynamics simulation
KW - Mutant
KW - SMUG1
KW - Stopped-flow kinetics
KW - Structure
KW - DOMAIN
KW - molecular dynamics simulation
KW - THYMINE
KW - REPAIR
KW - homology modeling
KW - fluorescence
KW - STRUCTURAL BASIS
KW - EXCISION
KW - human uracil-DNA glycosylase
KW - SPECIFICITY
KW - structure
KW - DAMAGE-RECOGNITION
KW - 5-HYDROXYMETHYLURACIL
KW - ENZYME
KW - stopped-flow kinetics
KW - mutant
KW - PROTEINS
UR - http://www.scopus.com/inward/record.url?scp=85071402677&partnerID=8YFLogxK
U2 - 10.3390/molecules24173133
DO - 10.3390/molecules24173133
M3 - Article
C2 - 31466351
AN - SCOPUS:85071402677
VL - 24
JO - Molecules
JF - Molecules
SN - 1420-3049
IS - 17
M1 - 3133
ER -
ID: 21346256