Disease relevance of cycI

• Reactions of isocytochrome c2 in the photosynthetic electron transfer chain of Rhodobacter sphaeroides [1].

High impact information on cycI

• While transcriptional linkage of adhI and cycI could suggest a function in a common metabolic pathway, isocytochrome c2 (periplasm) and AdhI (cytoplasm) are localized in separate compartments of R. sphaeroides [2].
• The cycI gene has been physically mapped to a region of chromosome I that is approximately 700 kb from the R. sphaeroides photosynthetic gene cluster [3].
• Construction of a defined cycI null mutant and complementation of several mutants with the cycI gene under the control of the cyt c2 promoter region indicate that an increase in the levels of isocyt c2 alone is necessary and sufficient for photosynthetic growth in the absence of cyt c2 [3].
• DNA sequence analysis of wild-type DNA that restores isocyt c2 production and photosynthetic growth to TP39 indicates that it encodes the isocyt c2 structural gene, cycI [3].
• These suppressors lacked detectable cyt c2, but they contained a new soluble cytochrome which was designated isocytochrome c2 (isocyt c2) that was not detectable in either cycA+ or cycA mutant cells [4].

References