Characterization of DbpA, an Escherichia coli DEAD box protein with ATP independent RNA unwinding activity.

AUTOR(ES)

Böddeker, N

RESUMO

DbpA is a putative Escherichia coli ATP dependent RNA helicase belonging to the family of DEAD box proteins. It hydrolyzes ATP in the presence of 23S ribosomal RNA and 93 bases in the peptidyl transferase center of 23S rRNA are sufficient to trigger 100% of the ATPase activity of DbpA. In the present study we characterized the ATPase and RNA unwinding activities of DbpA in more detail. We report that-in contrast to eIF-4A, the prototype of the DEAD box protein family-the ATPase and the helicase activities of DbpA are not coupled. Moreover, the RNA unwinding activity of DbpA is not specific for 23S rRNA, since DbpA is also able to unwind 16S rRNA hybrids. Furthermore, we determined that the ATPase activity of DbpA is triggered to a significant extent not only by the 93 bases of the 23S rRNA previously reported but also by other regions of the 23S rRNA molecule. Since all these regions of 23S rRNA are either part of the 'functional core' of the 50S ribosomal subunit or involved in the 50S assembly, DbpA may play an important role in the ribosomal assembly process.

Documentos Relacionados

• Visualization of unwinding activity of duplex RNA by DbpA, a DEAD box helicase, at single-molecule resolution by atomic force microscopy
• The "DEAD box" protein DbpA interacts specifically with the peptidyltransferase center in 23S rRNA.
• DbpA: a DEAD box protein specifically activated by 23s rRNA.
• Escherichia coli DbpA is an RNA helicase that requires hairpin 92 of 23S rRNA
• Interaction of Escherichia coli DbpA with 23S rRNA in different functional states of the enzyme