Biomaterial Database

The domains of mammalian base excision repair enzyme N-methylpurine-DNA glycosylase. Interaction, conformational change, and role in DNA binding and damage recognition. 1996

R Roy, and A Kumar, and J C Lee, and S Mitra

Sealy Center for Molecular Science and Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, Texas 77555, USA.

Repair of a variety of alkylated base adducts in DNA is initiated by their removal by N-methylpurine-DNA glycosylase. The 31-kDa mouse N-methylpurine-DNA glycosylase, derived by deletion of 48 amino acid residues from the 333-residue wild type protein without loss of activity, was analyzed for the presence of protease-resistant domains with specific roles in substrate binding and catalysis. Increasing proteolysis with trypsin generated first a 29-kDa polypeptide by removal of 42 amino-terminal residues, followed by production of 8-, 6-, and 13-kDa fragments with defined, nonoverlapping boundaries. The 8- and 13-kDa domains include the amino and carboxyl termini, respectively. Based on DNA-affinity chromatography and the protease protection assay, it appears that the 6- and 13-kDa domains are necessary for nontarget DNA binding and that the 8-kDa domain, in cooperation with the other two domains, participates in recognition of damaged bases. Furthermore, chemical cross-linking studies indicated that, in the presence of substrate DNA, the 8- and 6-kDa domains undergo conformational changes reflected by both protection from proteolysis and reduced availability of cysteine residues for the thiol-exchange reaction.

UI	MeSH Term	Description	Entries
D009699	N-Glycosyl Hydrolases	A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.	Glycoside Hydrolases, Nitrogen-linked,Hydrolases, N-Glycosyl,Nucleosidase,Nucleosidases,Nucleoside Hydrolase,Nitrogen-linked Glycoside Hydrolases,Nucleoside Hydrolases,Glycoside Hydrolases, Nitrogen linked,Hydrolase, Nucleoside,Hydrolases, N Glycosyl,Hydrolases, Nitrogen-linked Glycoside,Hydrolases, Nucleoside,N Glycosyl Hydrolases,Nitrogen linked Glycoside Hydrolases
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010449	Peptide Mapping	Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.	Fingerprints, Peptide,Peptide Fingerprinting,Protein Fingerprinting,Fingerprints, Protein,Fingerprint, Peptide,Fingerprint, Protein,Fingerprinting, Peptide,Fingerprinting, Protein,Mapping, Peptide,Peptide Fingerprint,Peptide Fingerprints,Protein Fingerprint,Protein Fingerprints
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D003852	Deoxyribonucleoproteins	Proteins conjugated with deoxyribonucleic acids (DNA) or specific DNA.
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
D004268	DNA-Binding Proteins	Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.	DNA Helix Destabilizing Proteins,DNA-Binding Protein,Single-Stranded DNA Binding Proteins,DNA Binding Protein,DNA Single-Stranded Binding Protein,SS DNA BP,Single-Stranded DNA-Binding Protein,Binding Protein, DNA,DNA Binding Proteins,DNA Single Stranded Binding Protein,DNA-Binding Protein, Single-Stranded,Protein, DNA-Binding,Single Stranded DNA Binding Protein,Single Stranded DNA Binding Proteins
D005091	Exons	The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.	Mini-Exon,Exon,Mini Exon,Mini-Exons
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic