GENETIC CONTROL OF CHLOROPHYLL BIOSYNTHESIS IN CHLAMYDOMONAS

作者：Wei-yeh Wang, Wenan Lee Wang, John E. Boynton, Nicholas Wright Gillham · 发表于：The Journal of Cell Biology · 年份：1974 · DOI：10.1083/jcb.63.3.806 · 被引用次数：63 · 研究领域：Photosynthetic Processes and Mechanisms、Porphyrin and Phthalocyanine Chemistry、Photoreceptor and optogenetics research

In this report we describe two nonallelic Mendelian protoporphyrin accumulating mutants br(s)-1 and br(c)-1. Results of experiments with these mutants lead us to postulate that porphyrin biosynthesis branches into light and dark steps between protoporphyrin-IX and magnesium protoporphyrin. We hypothesize that the br(c) locus controls a dark step while the br(s) locus either controls a step in the main pathway before the branch or mediates the preparation of the magnesium ion for its insertion into protoporphyrin-IX. The br(s)-1 mutant is thought to be light sensitive because a block prior to the branch point in the porphyrin pathway prevents chlorophyll formation in either the light or the dark. The br(c)-1 mutant, which also accumulates protoporphyrin in the dark, forms chlorophyll and chloroplast lamellae when transferred to the light, showing that function of the porphyrin pathway is normal in the light.