title: A primase subunit essential for efficient primer synthesis by an archaeal eukaryotic-type primase.
abstract: Archaea encode a eukaryotic-type primase comprising a catalytic subunit (PriS) and a noncatalytic subunit (PriL). Here we report the identification of a primase noncatalytic subunit, denoted PriX, from the hyperthermophilic archaeon Sulfolobus solfataricus. Like PriL, PriX is essential for the survival of the organism. The crystallographic analysis complemented by sensitive sequence comparisons shows that PriX is a diverged homologue of the C-terminal domain of PriL but lacks the iron-sulfur cluster. Phylogenomic analysis provides clues on the origin and evolution of PriX. PriX, PriL and PriS form a stable heterotrimer (PriSLX). Both PriSX and PriSLX show far greater affinity for nucleotide substrates and are substantially more active in primer synthesis than the PriSL heterodimer. In addition, PriL, but not PriX, facilitates primer extension by PriS. We propose that the catalytic activity of PriS is modulated through concerted interactions with the two noncatalytic subunits in primer synthesis.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing 100101, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Songying
authors.initials: S
authors.lastname: Ouyang
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA.
authors.forename: Kira S
authors.initials: KS
authors.lastname: Makarova
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing 100101, China.
authors.forename: Qiu
authors.initials: Q
authors.lastname: Xia
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing 100101, China.
authors.forename: Zhimeng
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing 100101, China.
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA.
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Koonin
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing 100101, China.
authors.forename: Li
authors.initials: L
authors.lastname: Huang
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics; D018360:Crystallography, X-Ray; D019915:DNA Primase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020745:Genome, Archaeal; D047468:Immunoprecipitation; D013058:Mass Spectrometry; D010802:Phylogeny; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D048229:Sulfolobus solfataricus
chemical_list: D019843:Archaeal Proteins; D021122:Protein Subunits; D019915:DNA Primase