Structural comparison of the prokaryotic ribosomal proteins L7/L12 and L30

• Published in: Proteins, structure, function, and bioinformatics Vol. 3; no. 4; p. 243
• Main Authors: Leijonmarck, M, Appelt, K, Badger, J, Liljas, A, Wilson, K S, White, S W
• Format: Journal Article
• Language: English
• Published: United States 1988
• Subjects: Amino Acid Sequence; Biological Evolution; Escherichia coli - analysis; Geobacillus stearothermophilus - analysis; Models, Molecular; Molecular Sequence Data; Protein Conformation; Ribosomal Proteins
• ISSN: 0887-3585; 1097-0134
• DOI: 10.1002/prot.340030405

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.