title: Crystal structure of a DNA-dependent RNA polymerase (DNA primase).
abstract: Primases are essential components of the DNA replication apparatus in every organism. They catalyze the synthesis of oligoribonucleotides on single-stranded DNA, which subsequently serve as primers for the replicative DNA polymerases. In contrast to bacterial primases, the archaeal enzymes are closely related to their eukaryotic counterparts. We have solved the crystal structure of the catalytic primase subunit from the hyperthermophilic archaeon Pyrococcus furiosus at 2.3 A resolution by multiwavelength anomalous dispersion methods. The structure shows a two-domain arrangement with a novel zinc knuckle motif located in the primase (prim) domain. In this first structure of a complete protein of the archaeal/eukaryotic primase family, the arrangement of the catalytically active residues resembles the active sites of various DNA polymerases that are unrelated in fold.
authors.affiliation: Max-Planck-Institut für Biochemie, Abteilung für Strukturforschung, Am Klopferspitz 18A, D-82152 Martinsried, Germany. augustin@biochem.mpg.de
authors.forename: M A
authors.initials: MA
authors.lastname: Augustin
authors.forename: R
authors.initials: R
authors.lastname: Huber
authors.forename: J T
authors.initials: JT
authors.lastname: Kaiser
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D019915:DNA Primase / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D020027:Pyrococcus furiosus / Q000201:enzymology*; D012643:Selenium / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015032:Zinc / Q000378:metabolism
chemical_list: D021122:Protein Subunits; D019915:DNA Primase; D012643:Selenium; D015032:Zinc