Structural highlights
Function
[DBPA_BACSU] DEAD-box RNA helicase involved in the assembly of the 50S ribosomal subunit. Has an RNA-dependent ATPase activity, which is specific for 23S rRNA, and a 3' to 5' RNA helicase activity that uses the energy of ATP hydrolysis to destabilize and unwind short rRNA duplexes (Probable).[1] [2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
DEAD-box RNA helicases of the bacterial DbpA subfamily are localized to their biological substrate when a carboxy-terminal RNA recognition motif domain binds tightly and specifically to a segment of 23S ribosomal RNA (rRNA) that includes hairpin 92 of the peptidyl transferase center. A complex between a fragment of 23S rRNA and the RNA binding domain (RBD) of the Bacillus subtilis DbpA protein YxiN was crystallized and its structure was determined to 2.9 A resolution, revealing an RNA recognition mode that differs from those observed with other RNA recognition motifs. The RBD is bound between two RNA strands at a three-way junction. Multiple phosphates of the RNA backbone interact with an electropositive band generated by lysines of the RBD. Nucleotides of the single-stranded loop of hairpin 92 interact with the RBD, including the guanosine base of G2553, which forms three hydrogen bonds with the peptide backbone. A G2553U mutation reduces the RNA binding affinity by 2 orders of magnitude, confirming that G2553 is a sequence specificity determinant in RNA binding. Binding of the RBD to 23S rRNA in the late stages of ribosome subunit maturation would position the ATP-binding duplex destabilization fragment of the protein for interaction with rRNA in the peptidyl transferase cleft of the subunit, allowing it to "melt out" unstable secondary structures and allow proper folding.
Structure of the RNA Binding Domain of a DEAD-Box Helicase Bound to Its Ribosomal RNA Target Reveals a Novel Mode of Recognition by an RNA Recognition Motif.,Hardin JW, Hu YX, McKay DB J Mol Biol. 2010 Jul 29. PMID:20673833[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kossen K, Uhlenbeck OC. Cloning and biochemical characterization of Bacillus subtilis YxiN, a DEAD protein specifically activated by 23S rRNA: delineation of a novel sub-family of bacterial DEAD proteins. Nucleic Acids Res. 1999 Oct 1;27(19):3811-20. PMID:10481020
- ↑ Karow AR, Klostermeier D. A conformational change in the helicase core is necessary but not sufficient for RNA unwinding by the DEAD box helicase YxiN. Nucleic Acids Res. 2009 Jul;37(13):4464-71. doi: 10.1093/nar/gkp397. Epub 2009, May 27. PMID:19474341 doi:http://dx.doi.org/10.1093/nar/gkp397
- ↑ Hardin JW, Hu YX, McKay DB. Structure of the RNA Binding Domain of a DEAD-Box Helicase Bound to Its Ribosomal RNA Target Reveals a Novel Mode of Recognition by an RNA Recognition Motif. J Mol Biol. 2010 Jul 29. PMID:20673833 doi:10.1016/j.jmb.2010.07.040
