Accumulation of protoporphyrin IX in light‐sensitive mutants of Escherichia coli

FEBS Letters

Inokuchi, Hachiro¹  Masuda, Tatsuru²  Miyamoto, Kazumasa¹  Tsuji, Hideo²  Nishimura, Koichi¹ 

[1] Department of Biophysics, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606-01, Japan;Department of Botany, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606-01, Japan

关键词: Light-sensitive mutant;    visA (hemH;    Protoporphyrin IX;    Ferrochelatase;    Proto IX;    protoporphyrin IX;    ΔALA;    σ-aminolevulinic acid;    LB medium;    Luria-Bertani medium;   

DOI  :  10.1016/0014-5793(92)81341-I

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The accumulation of protoporphyrin IX (Proto IX) in light-sensitive mutants of Escherichia coli was detected by spectrofluorimetry. Fluorescence emission and excitation spectra were recorded from extracts of bacterial cells. Proto IX clearly accumulated in cells with mutations in the visA (hemH) gene but not in the wild-type strain CA274 or in visA mutants that had been rendered light-resistant by introduction of the wild-type visA ⁺ gene. Accumulation of Proto IX was also not observed in cells with a mutation in the visB gene. These results confirm the hypothesis that the sensitivity of the visA mutants to light is caused by the abnormal accumulation of Proto IX, a substrate of ferrochelatase, as the result of a genetic defect in the gene for ferrochelatase.

【 授权许可】

Unknown