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Overexpression of RbfA in the absence of the KsgA checkpoint results in impaired translation initiation
Author(s) -
Connolly Keith,
Culver Gloria
Publication year - 2013
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12145
Subject(s) - ribosome biogenesis , biology , microbiology and biotechnology , ribosomal protein , ribosome , biogenesis , ribosomal rna , translation (biology) , methyltransferase , population , function (biology) , genetics , rna , messenger rna , gene , demography , sociology , methylation
Summary KsgA , a universally conserved small ribosomal subunit ( SSU ) rRNA methyltransferase, has recently been shown to facilitate a checkpoint within the ribosome maturation pathway. Under standard growth conditions removal of the KsgA checkpoint has a subtle impact on cell growth; yet, upon overexpresssion of RbfA , a ribosome maturation factor, KsgA becomes essential. Our results demonstrate the requirement of KsgA , in the presence of excess RbfA , both for the incorporation of ribosomal protein S21 to the developing SSU , and for final maturation of SSU rRNA . Also, when SSU biogenesis is perturbed by an imbalance in KsgA and RbfA , a population of 70 S ‐like particles accumulates that is compositionally, functionally and structurally distinct from mature 70 S ribosomes. Thus, our work suggests that KsgA and RbfA function together and are required for SSU maturation, and that additional checkpoints likely act to modulate malfunctional 70 S particle formation in vivo .