biostudies-literatureZappa SNIGMS NIH HHS229-50https://www.ebi.ac.uk/biostudies/studies/S-EPMC2883787biostudies-literatureUnknown675The purple anoxygenic photosynthetic bacterium Rhodobacter capsulatus is capable of growing in aerobic or anaerobic conditions, in the dark or using light, etc. Achieving versatile metabolic adaptations from respiration to photosynthesis requires the use of tetrapyrroles such as heme and bacteriochlorophyll, in order to carry oxygen, to transfer electrons, and to harvest light energy. A third tetrapyrrole, cobalamin (vitamin B(12)), is synthesized and used as a cofactor for many enzymes. Heme, bacteriochlorophyll, and vitamin B(12) constitute three major end products of the tetrapyrrole biosynthetic pathway in purple bacteria. Their respective synthesis involves a plethora of enzymes, several that have been characterized and several that are uncharacterized, as described in this review. ToAdvances in experimental medicine and biologyThe tetrapyrrole biosynthetic pathway and its regulation in Rhodobacter capsulatus.PMC2883787R37 GM040941R01 GM040941R37 GM040941-21Zappa SBauer CELi KfalseThe tetrapyrrole biosynthetic pathway and its regulation in Rhodobacter capsulatus.The purple anoxygenic photosynthetic bacterium Rhodobacter capsulatus is capable of growing in aerobic or anaerobic conditions, in the dark or using light, etc. Achieving versatile metabolic adaptations from respiration to photosynthesis requires the use of tetrapyrroles such as heme and bacteriochlorophyll, in order to carry oxygen, to transfer electrons, and to harvest light energy. A third tetrapyrrole, cobalamin (vitamin B(12)), is synthesized and used as a cofactor for many enzymes. Heme, bacteriochlorophyll, and vitamin B(12) constitute three major end products of the tetrapyrrole biosynthetic pathway in purple bacteria. Their respective synthesis involves a plethora of enzymes, several that have been characterized and several that are uncharacterized, as described in this review. To2010-01-01T00:00:00Z20102025-04-04T09:50:28.568Z2025-02-19T04:02:27.492ZS-EPMC28837872053274410.1007/978-1-4419-1528-3_13