title: Conformational study of the chromosomal protein MC1 from the archaebacterium Methanosarcina barkeri.
abstract: Methanogen chromosomal protein MC1 is a polypeptide of 93 amino acid residues (Mr 10,757) which represents the major protein associated with the DNA of the archaebacterium Methanosarcina barkeri and can protect DNA against thermal denaturation. The conformation of protein MC1 has been investigated by means of predictive methods, infrared spectroscopy, circular dichroism and tryptophan fluorescence studies. Protein MC1 has a low amount of alpha-helix but contains antiparallel beta-sheet strands. The larger hydrophobic cluster which contains tryptophan at position 61 appears buried in the protein. Addition of salts induces the unfolding of the protein and makes the tryptophan indole ring more rigid. With respect to its primary structure and its conformation, protein MC1 appears radically different from the chromosomal DNA-binding protein II (also called HU-type protein) in eubacteria.
authors.affiliation: Unité de Recherche Associée au Centre National de la Recherche Scientifique, Université de Lille II.
authors.forename: M
authors.initials: M
authors.lastname: Imbert
authors.forename: B
authors.initials: B
authors.lastname: Laine
authors.forename: N
authors.initials: N
authors.lastname: Helbecque
authors.forename: J P
authors.initials: JP
authors.lastname: Mornon
authors.forename: J P
authors.initials: JP
authors.lastname: Hénichart
authors.forename: P
authors.initials: P
authors.lastname: Sautière
mesh_terms: D000595:Amino Acid Sequence; D001105:Archaea / Q000032:analysis; D019843:Archaeal Proteins; D001419:Bacteria / Q000032:analysis; D001426:Bacterial Proteins / Q000302:isolation & purification; D002942:Circular Dichroism; D004268:DNA-Binding Proteins; D008969:Molecular Sequence Data; D009698:Nucleoproteins / Q000302:isolation & purification; D011487:Protein Conformation; D012261:Ribonucleoproteins; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C051211:HMb protein, Methanosarcina; D009698:Nucleoproteins; D012261:Ribonucleoproteins