A novel DNA polymerase homologous to Escherichia coli DNA polymerase I from a higher plant, rice (Oryza sativa L.).
A novel DNA polymerase, designated as OsPolI-like, has been identified from the higher plant, rice (Oryza sativa L. cv. Nipponbare). The OsPolI-like cDNA was 3765 bp in length, and the open reading frame encoded a predicted product of 977 amino acid residues with a molecular weight of 100 kDa. The OsPolI-like gene has been mapped to chromosome 8 and contains 12 exons and 11 introns. The encoded protein showed a high degree of sequence and structural homology to Escherichia coli pol I protein, but differed from DNA polymerase gamma and theta. The DNA polymerase domain of OsPolI-like showed DNA polymerase activity. Subcellular fractionation analysis suggested that the protein is localized in the plastid. Northern and western blotting, and in situ hybridization analyses demonstrated preferential expression of OsPolI-like in meristematic tissues such as shoot apical meristem, root apical meristem, leaf primordia and the marginal meristem. Interestingly, no expression was detected in mature leaves, although they have a high chloroplast content. These properties indicated that OsPolI-like is a novel plant DNA polymerase. The function of OsPolI-like is discussed in relation to plastid maturation.
Kimura
Seisuke
S
Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
Uchiyama
Yukinobu
Y
Kasai
Nobuyuki
N
Namekawa
Satoshi
S
Saotome
Ai
A
Ueda
Tadamasa
T
Ando
Tsuyu
T
Ishibashi
Toyotaka
T
Oshige
Masahiko
M
Furukawa
Tomoyuki
T
Yamamoto
Taichi
T
Hashimoto
Junji
J
Sakaguchi
Kengo
K
D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004256:DNA Polymerase I / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D005091:Exons / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D018547:Plant Stems / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D017422:Sequence Analysis, DNA
D018076:DNA, Complementary; D004256:DNA Polymerase I; D004259:DNA-Directed DNA Polymerase