Mapping and sequencing of an actively transcribed Euglena gracilis chloroplast gene (ccsA) homologous to the Arabidopsis thaliana nuclear gene cs(ch-42).

We mapped and sequenced a novel chloroplast gene encoding a protein (348 amino acids) which shows a high sequence identity with both the decoded nuclear cs(ch-42) gene product of Arabidopsis thaliana, and the C-terminal half of the decoded 'crtA' gene product of Rhodobacter capsulatus. The chloroplast gene (ccsA) is split (two exons) and transcribed into a stable mRNA of about 1200 nucleotides. The putative protein may be involved in the biosynthesis of photosynthetic pigments.