title: Structural comparison of the prokaryotic ribosomal proteins L7/L12 and L30.
abstract: The structures of two prokaryotic ribosomal proteins, the carboxyterminal half of L7/L12 from Escherichia coli (L12CTF) and L30 from Bacilus stearothermophilus display a remarkably similar fold in which alpha-helices pack onto one side of an antiparallel, three-stranded, beta-pleated sheet. A detailed comparison of the structures by least-squares methods reveals that more than two-thirds of the alpha carbons can be superimposed with a root mean square distance of 2.33 A. The principal difference is an extra alpha-helix in L12CTF. The sequences of the proteins display a distinct conservation in regions which are crucial to the common fold, in particular the hydrophobic core. It is proposed that the similarity is a result of divergent evolution.
mesh_terms: D000595:Amino Acid Sequence; D005075:Biological Evolution; D004926:Escherichia coli / Q000032:analysis; D001411:Geobacillus stearothermophilus / Q000032:analysis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012269:Ribosomal Proteins
chemical_list: D012269:Ribosomal Proteins; C035201:ribosomal protein L30; C016700:ribosomal protein L7-L12