{"doi":"10.1101/2021.02.16.431308","title":"The evolution of the cytochrome\n                  <i>c</i>\n                  <sub>6</sub>\n                  family of photosynthetic electron transfer proteins","abstract":"<jats:title>Abstract</jats:title>\n                <jats:p>\n                  During photosynthesis, electrons are transferred between the cytochrome\n                  <jats:italic>b</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  <jats:italic>f</jats:italic>\n                  complex and photosystem I. This is carried out by the protein plastocyanin in plant chloroplasts. In contrast, electron transfer can be carried out by either plastocyanin or cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  in many cyanobacteria and eukaryotic algal species. There are three further cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  homologues: cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6A</jats:sub>\n                  in plants and green algae, and cytochromes\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6B</jats:sub>\n                  and\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6C</jats:sub>\n                  in cyanobacteria. The function of these proteins is unknown. Here, we present a comprehensive analysis of the evolutionary relationship between the members of the cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  family in photosynthetic organisms. Our phylogenetic analyses show that cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6B</jats:sub>\n                  and cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6C</jats:sub>\n                  are likely to be orthologues that arose from a duplication of cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  , but that there is no evidence for separate origins for cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6B</jats:sub>\n                  and\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6C</jats:sub>\n                  . We therefore propose re-naming cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6C</jats:sub>\n                  as cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6B</jats:sub>\n                  . We show that cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6A</jats:sub>\n                  is likely to have arisen from cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6B</jats:sub>\n                  rather than by an independent duplication of cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  , and present evidence for an independent origin of a protein with some of the features of cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6A</jats:sub>\n                  in peridinin dinoflagellates. We conclude with a new comprehensive model of the evolution of the cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  family which is an integral part of understanding the function of the enigmatic cytochrome\n                  <jats:italic>c</jats:italic>\n                  <jats:sub>6</jats:sub>\n                  homologues.\n                </jats:p>","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":null,"id":35567,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":1,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":181892,"name":"Darius Kosmützky","orcid":null,"position":1,"is_corresponding":false},{"id":181893,"name":"R. Ellen R. Nisbet","orcid":"0000-0003-4487-196X","position":2,"is_corresponding":false},{"id":181894,"name":"Christopher J. Howe","orcid":"0000-0002-6975-8640","position":3,"is_corresponding":false},{"id":181891,"name":"Barnaby Slater","orcid":"0000-0001-9922-8563","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":0.0,"endowment":0.0,"datacite_reuse_total":1,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"18998881","pmcid":null,"openalex_id":"https://openalex.org/W3130141317","authors":[],"funders":[{"funder_name":"UK Research and Innovation","grant_id":"BB/M011194/1","title":"Cambridge Doctoral Training Partnership - 2"}],"total_grants":1,"fwci":null,"citation_percentile":null,"influential_citations":0,"citation_trend":[],"oa_status":"green","license":"https://www.biorxiv.org/about/FAQ#license","oa_locations":[{"url":"https://www.biorxiv.org/content/biorxiv/early/2021/02/17/2021.02.16.431308.full.pdf","host_type":"repository"},{"url":"https://www.biorxiv.org/content/biorxiv/early/2021/02/17/2021.02.16.431308.full.pdf","host_type":"repository"},{"url":"https://syndication.highwire.org/content/doi/10.1101/2021.02.16.431308","host_type":"publisher"},{"url":"https://doi.org/10.1101/2021.02.16.431308","host_type":"repository"},{"url":"https://nottingham-repository.worktribe.com/preview/5718733/evab146.pdf","host_type":""},{"url":"https://doi.org/10.1093/gbe/evab146","host_type":""},{"url":"https://academic.oup.com/gbe/article-pdf/13/8/evab146/39680739/evab146.pdf","host_type":""},{"url":"https://dx.doi.org/10.17863/cam.71642","host_type":""},{"url":"https://pubmed.ncbi.nlm.nih.gov/34165554","host_type":""},{"url":"http://dx.doi.org/10.1093/gbe/evab146","host_type":""},{"url":"https://dx.doi.org/10.1101/2021.02.16.431308","host_type":""},{"url":"https://dx.doi.org/10.1093/gbe/evab146","host_type":""},{"url":"https://www.repository.cam.ac.uk/handle/1810/324186","host_type":""},{"url":"https://doi.org/10.17863/cam.71642","host_type":""}],"fields_of_study":["Photosynthetic Processes and Mechanisms","Protist diversity and phylogeny","Algal biology and biofuel production","0301 basic medicine","03 medical and health sciences"],"mesh_terms":[],"keywords":["Plastocyanin","Cytochrome b6f complex","Cytochrome f","Cytochrome","Cytochrome c","Cytochrome b","Cytochrome C1","Biology","Coenzyme Q – cytochrome c reductase","Cytochrome P450 reductase","Cytochrome c oxidase","Photosynthesis","Photosystem I","Biochemistry","Photosystem II","Phylogenetic tree","Gene","Mitochondrion","Enzyme","Electron Transport","Cytochromes c6","evolutionary model","Cytochromes","Electrons","phylogeny","Research Article"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Life in Land"}],"linked_datasets":[{"doi":"10.17863/cam.71642","title":"The Evolution of the Cytochrome c6 Family of Photosynthetic Electron Transfer Proteins.","publisher":"Oxford University Press (OUP)","resource_type":"JournalArticle"}],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-10T04:58:53.294399Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}