Identification and characterization of the sec-A protein homologue in the cyanobacterium Synechococcus PCC7942.
The secA gene product mediates protein translocation across the cytoplasmic membrane in Escherichia coli. We have cloned a gene homologous to secA from the genome of the cyanobacterium Synechococcus PCC7942. The deduced amino acid sequence, 948 amino acids long, shows 43% homology with that of the E. coli secA and 47-48% homology with those of the algal plastid secA genes. Upon subcellular fractionation, the cyanobacterial SecA protein was mainly found as soluble homodimer in the cytosol, but the remaining small but distinct fraction was associated with both the cytoplasmic and thylakoid membranes. The SecA protein likely participates in protein translocation across both the cytoplasmic and thylakoid membranes in cyanobacterial cells.
Nakai
M
M
Department of Chemistry, Faculty of Science, Nagoya University, Japan.
Nohara
T
T
Sugita
D
D
Endo
T
T
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002736:Chloroplasts / Q000378:metabolism; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D007425:Intracellular Membranes / Q000378:metabolism; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D017386:Sequence Homology, Amino Acid; D012995:Solubility
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins