SrmB, a DEAD-box helicase involved in Escherichia coli ribosome assembly, is specifically targeted to 23S rRNA in vivo.

ABSTRACT: DEAD-box proteins play specific roles in remodeling RNA or ribonucleoprotein complexes. Yet, in vitro, they generally behave as nonspecific RNA-dependent ATPases, raising the question of what determines their specificity in vivo. SrmB, one of the five Escherichia coli DEAD-box proteins, participates in the assembly of the large ribosomal subunit. Moreover, when overexpressed, it compensates for a mutation in L24, the ribosomal protein (r-protein) thought to initiate assembly. Here, using the tandem affinity purification (TAP) procedure, we show that SrmB forms a complex with r-proteins L4, L24 and a region near the 5'-end of 23S rRNA that binds these proteins. In vitro reconstitution experiments show that the stability of this complex reflects cooperative interactions of SrmB with L4, L24

SUBMITTER: Trubetskoy D 

PROVIDER: S-EPMC2770661 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature