Cloning of two sea urchin DNA-binding proteins involved in mitochondrial DNA replication and transcription.
The cloning of the cDNA for two mitochondrial proteins involved in sea urchin mtDNA replication and transcription is reported here. The cDNA for the mitochondrial D-loop binding protein (mtDBP) from the sea urchin Strongylocentrotus purpuratus has been cloned by a polymerase chain reaction-based approach. The protein displays a very high similarity with the Paracentrotus lividus homologue as it contains also the two leucine zipper-like domains which are thought to be involved in intramolecular interactions needed to expose the two DNA binding domains in the correct position for contacting DNA. The cDNA for the mitochondrial single-stranded DNA-binding protein (mtSSB) from P. lividus has been also cloned by a similar approach. The precursor protein is 146 amino acids long with a presequence of 16 residues. The deduced amino acid sequence shows the highest homology with the Xenopus laevis protein and the lowest with the Drosophila mtSSB. The computer modeling of the tertiary structure of P. lividus mtSSB shows a structure very similar to that experimentally determined for human mtSSB, with the conservation of the main residues involved in protein tetramerization and in DNA binding.
Loguercio Polosa
Paola
P
Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, and Centro Studi sui Mitocondri e Metabolismo Energetico, CNR Bari, Via Orabona 4, 70125 Bari, Italy.
Megli
Fiammetta
F
Di Ponzio
Barbara
B
Gadaleta
Maria Nicola
MN
Cantatore
Palmiro
P
Roberti
Marina
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004261:DNA Replication / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012617:Sea Urchins / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic / Q000235:genetics
D018076:DNA, Complementary; D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins