Alterations in the two globular domains or in the connecting alpha-helix of bacterial ribosomal protein L9 induces +1 frameshifts.
2007 (English)In: J Bacteriol, ISSN 0021-9193, Vol. 189, no 19, 7024-31 p.Article in journal (Refereed) Published
The ribosomal 50S subunit protein L9, encoded by the gene rplI, is an elongated protein with an alpha-helix connecting the N- and C-terminal globular domains. We isolated rplI mutants that suppress the +1 frameshift mutation hisC3072 in Salmonella enterica serovar Typhimurium. These mutants have amino acid substitutions in the N-terminal domain (G24D) or in the C-terminal domain (I94S, A102D, G126V, and F132S) of L9. In addition, different one-base deletions in rplI altered either the final portion of the C terminus or removed the C-terminal domain with or without the connecting alpha-helix. An alanine-to-proline substitution at position 59 (A59P), which breaks the alpha-helix between the globular domains, induced +1 frameshifting, suggesting that the geometrical relationship between the N and C domains is important to maintain the reading frame. Except for the alterations G126V in the C terminus and A59P in the connecting alpha-helix, our results confirm earlier results obtained by using the phage T4 gene 60-based system to monitor bypassing. The way rplI mutations suppress various frameshift mutations suggests that bypassing of many codons from several takeoff and landing sites occurred instead of a specific frameshift forward at overlapping codons.
Place, publisher, year, edition, pages
2007. Vol. 189, no 19, 7024-31 p.
IdentifiersURN: urn:nbn:se:umu:diva-16716PubMedID: 17660285OAI: oai:DiVA.org:umu-16716DiVA: diva2:156389