@article{mbs:/content/journal/micro/10.1099/13500872-140-5-1151, author = "Ghassemian, Majid and Wong, Bess and Ferreira, Fernando and Markley, John L. and Straus, Neil A.", title = "Cloning, sequencing and transcriptional studies of the genes for cytochrome c-553 and plastocyanin from Anabaena sp. PCC 7120", journal= "Microbiology", year = "1994", volume = "140", number = "5", pages = "1151-1159", doi = "https://doi.org/10.1099/13500872-140-5-1151", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-140-5-1151", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "gene regulation", keywords = "plastocyanin", keywords = "Anabaena sp. PCC 7120", keywords = "algae", keywords = "cytochrome c-553", keywords = "cyanobacteria", abstract = "In some cyanobacteria and eukaryotic algae, cytochrome c-553 (c-552) and plastocyanin function as alternative electron carriers between the cytochrome b 6 -f complex and Photosystem I. In these organisms plastocyanin is the electron carrier under copper-replete conditions, and cytochrome c-553 is the electron carrier during copper deprivation. In this paper we report the cloning, sequencing and transcriptional analysis of the genes for cytochrome c-553 and plastocyanin from Anabaena sp. PCC 7120. The gene for cytochrome c-553 encodes a preprotein containing 111 amino acids with a predicted n-terminal transit peptide sequence of 25 amino acids. The gene for plastocyanin encodes a preprotein containing 139 amino acids with a n-terminal transit peptide sequence of 34 amino acids. RNA transcript analyses indicate that the expression of the genes for cytochrome c-553 (petJ) and plastocyanin (petE) are regulated in reciprocal ways in response to copper concentration. In copper-replete conditions, petJ is expressed at very low levels, but is transcribed at high levels under copper deprivation; petE is down-regulated in the absence of copper, but is rapidly up-regulated when copper is added back to the medium.", }