An acidic, alanine‐rich 50 S ribosomal protein from Halobacterium cutirubrum: Amino acid sequence homology with Escherichia coli proteins L7 and L12

Chemistry and biology ofE. coli ribosomal protein L12

“…Thus, a similar type protein(s) has also been found in Halobacteria cutirubrum (43)(44)(45), Bacillus stearothermophilus (46,47), yeast (48), rat liver (49), chicken liver (50), and Arternia salina (51). The protein from B. stearothermophilus (A2) can substitute for E. coli L7/L12 on the E. coli ribosome and support protein synthesis [Table 3 (52)].…”

“…There appears to be little homology between E. coli and A. salina except for an alanine rich area in both proteins (54). Oda et al (44) have pointed out that although the respective proteins from E. coli and H. cutirubrum show no immunological or biological cross-reactivity, when the first amino acid of HL20 is aligned with residue 35 ofE. coli L7/LI2, then 13 of the first 30 amino acids of HL20 are identical to the E. coli L7/L12 amino acids.…”

Methanogens and the diversity of archaebacteria.

“…However, comparisons with eubacterial and eucaryotic ribosomes are hampered by the complexity of the ribosome and incomplete sets of data on ribosomal proteins from other kingdoms. Although immunological and protein sequence data have identified a number of homologies with eubacterial and eucaryotic proteins, these studies are far from complete (9,241,308,310,348,398,401,402,531). The early observation that ribosomal proteins of archaebacteria are unusually acidic is well correlated with the intracytoplasmic concentrations of ions in halobacteria and some methanogens and is probably not of major phylogenetic significance (196).…”

“…The early observation that ribosomal proteins of archaebacteria are unusually acidic is well correlated with the intracytoplasmic concentrations of ions in halobacteria and some methanogens and is probably not of major phylogenetic significance (196). The archaebacterial ribosomal "A" proteins, whose complete sequence is known, has substantial homology to the eucaryotic "A" protein and much less homology to the eubacterial equivalent, L12 (308,309,348). Similarly, the archaebacterial 5S RNA-binding proteins have more sequence homology to the eucaryotic than to the eubacterial proteins (9,241).…”

A comparison of the alanine‐rich sequences of the L7/L12‐ribosomal proteins from rat liver, Artemia salina and Escherichia coli, with the amino‐terminal region of the alkali light chain A1 from rabbit myosin

“…wt acidic protein, which is involved in elongation factor-dependent GTP hydrolysis [ 1 ]. A similar protein has been detected in the ribosomes of a number of eucaryotic organisms [2], and primary structure studies of the proteins of procaryotes and eucaryotes have been initiated [3][4][5]. Recently, it was found that the aminoterminal region of L7/L12-protein from Artemia salina and Saccharomyces cerevisiae shows a sequence homology with the corresponding region of the protein from Halobacterium cutirubrum [6].…”