title: Primary structure of the chromosomal proteins MC1a, MC1b, and MC1c from the archaebacterium Methanothrix soehngenii.
abstract: The chromosomal protein MC1 of Methanothrix soehngenii is a family of three variants a, b, and c. These are small basic polypeptides of 89, 87, and 90 residues, respectively. Their primary structures have been determined from automated sequence analyses of the intact proteins and from structural data provided by peptides derived from the variants by cleavage at aspartic acid, glutamic acid, arginine, and methionine residues. By comparison with variant b taken as reference, variants a and c present 18 and 24 differences, respectively. The extent of sequence homologies between protein MC1 from M. soehngenii and proteins MC1 from two other species of Methanosarcinaceae is only 60%. The sequences 17-35 and 45-58 of the protein MC1 appear well conserved. Deletions are observed in region 36-44. Many changes, most of them nonconservative, occur in the carboxyl-terminal third of the protein. However, proline residues at positions 68, 72, 76, and 82 remain strictly conserved. Predictive methods for secondary structures indicate a low content of alpha helix and beta sheet structures in proteins MC1.
authors.affiliation: Université de Lille II, Unité de Recherche Associée 409 au Centre National de la Recherche Scientifique.
authors.forename: F
authors.initials: F
authors.lastname: Chartier
authors.forename: B
authors.initials: B
authors.lastname: Laine
authors.forename: D
authors.initials: D
authors.lastname: Bélaïche
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 / Q000378:metabolism; D003488:Cyanogen Bromide; D010450:Endopeptidases; D019605:Euryarchaeota / Q000032:analysis*; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009698:Nucleoproteins / Q000378:metabolism; D011487:Protein Conformation; D012261:Ribonucleoproteins; D012689:Sequence Homology, Nucleic Acid; D012697:Serine Endopeptidases
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; C051211:HMb protein, Methanosarcina; D009698:Nucleoproteins; D012261:Ribonucleoproteins; D010450:Endopeptidases; C044499:submandibular proteinase A; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D003488:Cyanogen Bromide