title: Domain structure of vaccinia DNA ligase.
abstract: The 552 amino acid vaccinia virus DNA ligase consists of three structural domains defined by partial proteolysis: (i) an amino-terminal 175 amino acid segment that is susceptible to digestion with chymotrypsin and trypsin; (ii) a protease-resistant central domain that contains the active site of nucleotidyl transfer (Lys-231); (iii) a protease-resistant carboxyl domain. The two protease-resistant domains are separated by a protease-sensitive interdomain bridge from positions 296 to 307. Adenylyltransferase and DNA ligation activities are preserved when the N-terminal 200 amino acids are deleted. However, the truncated form of vaccinia ligase has a reduced catalytic rate in strand joining and a lower affinity for DNA than does the full-sized enzyme. The 350 amino acid catalytic core of the vaccinia ligase is similar in size and protease-sensitivity to the full-length bacteriophage T7 DNA ligase.
authors.affiliation: Molecular Biology Program, Sloan-Kettering Institute, New York 10021, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sekiguchi
authors.forename: S
authors.initials: S
authors.lastname: Shuman
mesh_terms: D000255:Adenosine Triphosphate / Q000502:physiology; D000595:Amino Acid Sequence; D011088:DNA Ligases / Q000737:chemistry* / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D010450:Endopeptidases; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000737:chemistry; D011485:Protein Binding / Q000235:genetics; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D017384:Sequence Deletion; D014616:Vaccinia virus / Q000201:enzymology*
chemical_list: D004279:DNA, Viral; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D009713:Nucleotidyltransferases; D010450:Endopeptidases; D011088:DNA Ligases