Chung, JH Back, JH Park, YI Han, YS 2024-01-21T12:06:10Z 2024-01-21T12:06:10Z 2021-09-04 2001-07-15 0305-1048 https://pubs.kist.re.kr/handle/201004/140311 A novel dNTP pyrophosphatase, Mj0226 from Methanococcus jannaschii, which catalyzes the hydrolysis of nucleoside triphosphates to the monophosphate and PPi, has been characterized. Mj0226 protein catalyzes hydrolysis of two major substrates, dITP and XTP, suggesting that the 6-keto group of hypoxanthine and xanthine is critical for interaction with the protein. Under optimal reaction conditions the k(cat)/K-m value for these substrates was similar to 10 000 times that with dATP. Neither endonuclease nor 3'-exonuclease activities were detected in this protein. Interestingly, dITP was efficiently inserted opposite a dC residue in a DNA template and four dNTPs were also incorporated opposite a hypoxanthine residue in template DNA by DNA polymerase I. Two protein homologs of Mj0226 from Escherichia coli and Archaeoglobus fulgidus were also cloned and purified. These have catalytic activities similar to Mj0226 protein under optimal conditions. The implications of these results have significance in understanding how homologous proteins, including Mj0226, act biologically in many organisms. It seems likely that Mj0226 and its homologs have a major role in preventing mutations caused by incorporation of dITP and XTP formed spontaneously in the nucleotide pool into DNA. This report is the first identification and functional characterization of an enzyme hydrolyzing non-canonical nucleotides, dITP and XTP. English OXFORD UNIV PRESS COLI ENDONUCLEASE-V ESCHERICHIA-COLI SACCHAROMYCES-CEREVISIAE TRIPHOSPHATE PYROPHOSPHOHYDROLASE DEOXYRIBONUCLEIC-ACID DUTP PYROPHOSPHATASE DNA-SYNTHESIS 6-N-HYDROXYLAMINOPURINE DEOXYINOSINE GLYCOSYLASE Biochemical characterization of a novel hypoxanthine/xanthine dNTP pyrophosphatase from Methanococcus jannaschii Article 10.1093/nar/29.14.3099 1 NUCLEIC ACIDS RESEARCH, v.29, no.14, pp.3099 - 3107 NUCLEIC ACIDS RESEARCH 29 14 3099 3107 scie scopus 000170105300020 2-s2.0-0035879027 Biochemistry & Molecular Biology Biochemistry & Molecular Biology Article COLI ENDONUCLEASE-V ESCHERICHIA-COLI SACCHAROMYCES-CEREVISIAE TRIPHOSPHATE PYROPHOSPHOHYDROLASE DEOXYRIBONUCLEIC-ACID DUTP PYROPHOSPHATASE DNA-SYNTHESIS 6-N-HYDROXYLAMINOPURINE DEOXYINOSINE GLYCOSYLASE dNTP pyrophosphatase