{"doi":"10.1128/jb.00395-07","title":"Structure and Function of Cold Shock Proteins in Archaea","abstract":"<jats:title>ABSTRACT</jats:title>\n                  <jats:p>\n                    Archaea are abundant and drive critical microbial processes in the Earth's cold biosphere. Despite this, not enough is known about the molecular mechanisms of cold adaptation and no biochemical studies have been performed on stenopsychrophilic archaea (e.g.,\n                    <jats:italic>Methanogenium frigidum</jats:italic>\n                    ). This study examined the structural and functional properties of cold shock proteins (Csps) from archaea, including biochemical analysis of the Csp from\n                    <jats:italic>M. frigidum. csp</jats:italic>\n                    genes are present in most bacteria and some eucarya but absent from most archaeal genome sequences, most notably, those of all archaeal thermophiles and hyperthermophiles. In bacteria, Csps are small, nucleic acid binding proteins involved in a variety of cellular processes, such as transcription. In this study, archaeal Csp function was assessed by examining the ability of\n                    <jats:italic>csp</jats:italic>\n                    genes from psychrophilic and mesophilic\n                    <jats:italic>Euryarchaeota</jats:italic>\n                    and\n                    <jats:italic>Crenarchaeota</jats:italic>\n                    to complement a cold-sensitive growth defect in\n                    <jats:italic>Escherichia coli</jats:italic>\n                    . In addition, an archaeal gene with a cold shock domain (CSD) fold but little sequence identity to Csps was also examined. Genes encoding Csps or a CSD structural analog from three psychrophilic archaea rescued the\n                    <jats:italic>E. coli</jats:italic>\n                    growth defect. The three proteins were predicted to have a higher content of solvent-exposed basic residues than the noncomplementing proteins, and the basic residues were located on the nucleic acid binding surface, similar to their arrangement in\n                    <jats:italic>E. coli</jats:italic>\n                    CspA. The\n                    <jats:italic>M. frigidum</jats:italic>\n                    Csp was purified and found to be a single-domain protein that folds by a reversible two-state mechanism and to exhibit a low conformational stability typical of cold-adapted proteins. Moreover,\n                    <jats:italic>M. frigidum</jats:italic>\n                    Csp was characterized as binding\n                    <jats:italic>E. coli</jats:italic>\n                    single-stranded RNA, consistent with its ability to complement function in\n                    <jats:italic>E. coli</jats:italic>\n                    . The studies show that some Csp and CSD fold proteins have retained sufficient similarity throughout evolution in the\n                    <jats:italic>Archaea</jats:italic>\n                    to be able to function effectively in the\n                    <jats:italic>Bacteria</jats:italic>\n                    and that the function of the archaeal proteins relates to cold adaptation. The initial biochemical analysis of\n                    <jats:italic>M. frigidum</jats:italic>\n                    Csp has developed a platform for further characterization and demonstrates the potential for expanding molecular studies of proteins from this important archaeal stenopsychrophile.\n                  </jats:p>","journal":"Journal of Bacteriology","year":2007,"id":19453,"datarank":2.618124014019782,"base_score":4.248495242049359,"endowment":4.248495242049359,"self_citation_contribution":0.637274286307404,"citation_network_contribution":1.9808497277123782,"self_endowment_contribution":0.637274286307404,"citer_contribution":1.9808497277123782,"corpus_percentile":null,"corpus_rank":null,"citation_count":69,"citer_count":60,"citers_with_citation_signal":55,"citers_with_endowment":55,"datacite_reuse_total":0,"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":131801,"name":"Paul M. G. Curmi","orcid":null,"position":1,"is_corresponding":false},{"id":131802,"name":"Khawar S. Siddiqui","orcid":null,"position":2,"is_corresponding":false},{"id":116316,"name":"Anne Poljak","orcid":null,"position":3,"is_corresponding":false},{"id":131803,"name":"Ed DeLong","orcid":null,"position":4,"is_corresponding":false},{"id":131804,"name":"Shiladitya DasSarma","orcid":null,"position":5,"is_corresponding":false},{"id":131805,"name":"Ricardo Cavicchioli","orcid":null,"position":6,"is_corresponding":false},{"id":131800,"name":"Laura Giaquinto","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":4.248495242049359,"endowment":4.248495242049359,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"17545280","pmcid":"PMC1951829","openalex_id":"https://openalex.org/W1974920184","authors":[],"funders":[],"total_grants":0,"fwci":2.0502,"citation_percentile":0.86379323,"influential_citations":2,"citation_trend":[{"year":2012,"count":7},{"year":2013,"count":3},{"year":2014,"count":3},{"year":2015,"count":1},{"year":2016,"count":4},{"year":2017,"count":5},{"year":2018,"count":6},{"year":2019,"count":5},{"year":2020,"count":5},{"year":2021,"count":6},{"year":2022,"count":4},{"year":2023,"count":3},{"year":2024,"count":1},{"year":2025,"count":1},{"year":2026,"count":1}],"oa_status":"green","license":"https://journals.asm.org/non-commercial-tdm-license","oa_locations":[{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/1951829","host_type":"repository"},{"url":"https://doi.org/10.1128/jb.00395-07","host_type":"GREEN"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/1951829","host_type":"repository"},{"url":"https://journals.asm.org/doi/pdf/10.1128/JB.00395-07","host_type":"publisher"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17545280","host_type":"repository"}],"fields_of_study":["Enzyme Structure and Function","Protein Structure and Dynamics","Yersinia bacterium, plague, ectoparasites research","Medicine","Biology","Environmental Science","Amino Acid Sequence","Archaeal Proteins","Cold Temperature","Crenarchaeota","Escherichia coli","Euryarchaeota","Genetic Complementation Test","Models, Molecular","Molecular Sequence Data","Mutation","Phylogeny","Protein Binding","Protein Conformation","RNA","RNA-Binding Proteins","Sequence Homology, Amino Acid"],"mesh_terms":["Amino Acid Sequence","Cold Temperature","Escherichia coli","Genetic Complementation Test","Models, Molecular","Molecular Sequence Data","Mutation","Phylogeny","Protein Binding","Protein Conformation","RNA","RNA-Binding Proteins","Sequence Homology, Amino Acid","Euryarchaeota","Crenarchaeota","Archaeal Proteins"],"keywords":["Cold-shock domain","Archaea","Biology","Crenarchaeota","Hyperthermophile","Psychrophile","Thermophile","Euryarchaeota","Biochemistry","Gene","Bacteria","Escherichia coli","Genetics","RNA"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Life below water"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-04T04:10:38.600643Z","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":[]}