Studies on the role of HtpG in the tetrapyrrole biosynthesis pathway of the cyanobacterium Synechococcus elongatus PCC 7942.
In cyanobacterium Synechococcus elongatus PCC 7942, we observed that htpG-overexpression caused remarkable growth inhibition. In addition, subcellular fractionation experiments showed that HtpG was localized in the membrane fraction. To understand its function in cyanobacteria, we carried out yeast two-hybrid screening to identify specific proteins interacting with HtpG, and found out, HemE, uroporphyrinogen decarboxylase. When compared to the wild-type strain, the htpG-null mutant and -overexpressing strains exhibited higher and lower cytosolic HemE activity, based on the coproporphyrin production, respectively. These results strongly suggest that HtpG is involved in the regulation of tetrapyrrole biosynthesis through interacting with HemE protein.
Watanabe
Satoru
S
Department of Bioscience, Tokyo University of Agriculture, Sakuragaoka 1-1-1, Setagaya-ku, Tokyo 156-8502, Japan.
Kobayashi
Toshiaki
T
Saito
Masakazu
M
Sato
Masumi
M
Nimura-Matsune
Kaori
K
Chibazakura
Taku
T
Taketani
Shigeru
S
Nakamoto
Hitoshi
H
Yoshikawa
Hirofumi
H
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D046940:Synechococcus / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D045725:Tetrapyrroles / Q000096:biosynthesis*; D014575:Uroporphyrinogen Decarboxylase / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D018841:HSP90 Heat-Shock Proteins; D045725:Tetrapyrroles; C066720:HtpG protein, bacteria; D014575:Uroporphyrinogen Decarboxylase