title: Identification and chromosomal localization of murine ORC3, a new member of the mouse origin recognition complex.
abstract: A new member of the murine origin recognition complex (ORC) related to Saccharomyces cerevisiae ORC3 has been cloned. Transcription of ORC3 is not suppressed in mouse NIH3T3 fibroblasts made quiescent by serum starvation. The transcription level of the ORC3 gene is constantly high in all phases of the cell cycle. Murine ORC3 protein contains a putative nuclear localization signal and a non-basic helix-loop-helix motif. Both motifs are conserved in eukaryotes. A potential dimerization partner of ORC3p in the murine ORC complex is ORC1p which also contains an HLH motif. This HLH motif is also highly conserved in all eukaryotic ORC1 proteins. Comparison of murine ORC3p with other ORC3-related proteins shows high amino acid homology and motif conservation leading to the conclusion that ORC3p is part of the initiation machinery conserved in eukaryotes. The mouse ORC3 gene Orc3 was assigned to mouse chromosome 4A3 by fluorescence in situ hybridization (FISH) analysis.
authors.affiliation: Institute of Biochemistry, Biozentrum, University of Würzburg, Würzburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Springer
authors.forename: I
authors.initials: I
authors.lastname: Nanda
authors.forename: K
authors.initials: K
authors.lastname: Hoehn
authors.forename: M
authors.initials: M
authors.lastname: Schmid
authors.forename: F
authors.initials: F
authors.lastname: Grummt
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D002453:Cell Cycle; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D018257:Helix-Loop-Helix Motifs / Q000502:physiology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D008969:Molecular Sequence Data; D051738:Origin Recognition Complex; D020161:Physical Chromosome Mapping; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D018741:Replication Origin / Q000235:genetics / Q000502:physiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C497225:ORC3 protein, human; C497228:Orc1 protein, mouse; C497229:Orc3 protein, mouse; D051738:Origin Recognition Complex; D012333:RNA, Messenger