Bacterial type B RNase P: functional characterization of the L5.1-L15.1 tertiary contact and antisense inhibition.

Ribonuclease P is the ubiquitous endonuclease that generates the mature 5'-ends of precursor tRNAs. In bacteria, the enzyme is composed of a catalytic RNA (∼400 nucleotides) and a small essential protein subunit (∼13 kDa). Most bacterial RNase P RNAs (P RNAs) belong to the architectural type A; type B RNase P RNA is confined to the low-G+C Gram-positive bacteria.

Structure of an A-form RNA duplex obtained by degradation of 6S RNA in a crystallization droplet.

In the course of a crystallographic study of a 132 nt variant of Aquifex aeolicus 6S RNA, a crystal structure of an A-form RNA duplex containing 12 base pairs was solved at a resolution of 2.6 Å. In fact, the RNA duplex is part of the 6S RNA and was obtained by accidental but precise degradation of the 6S RNA in a crystallization droplet.

Revision of anterior cruciate ligament reconstruction with patellar tendon allograft and autograft: 2- and 5-year results.

Introduction: The most common failure reasons of an anterior cruciate ligament (ACL) graft are incorrect positioning of the drill channels and insufficient fixation. In many cases, one-stage revision with patellar tendon graft and the appropriate corrections are possible. For previous use of the ipsilateral patellar tendon third, an allograft seems favorable for reconstruction.

A pRNA-induced structural rearrangement triggers 6S-1 RNA release from RNA polymerase in Bacillus subtilis.

Bacillus subtilis 6S-1 RNA binds to the housekeeping RNA polymerase (σ(A)-RNAP) and directs transcription of short 'product' RNAs (pRNAs). Here, we demonstrate that once newly synthesized pRNAs form a sufficiently stable duplex with 6S-1 RNA, a structural rearrangement is induced in cis, which involves base-pairing between sequences in the 5'-portion of the central bulge and nucleotides that become available as a result of pRNA invasion. The rearrangement decreases 6S-1 RNA affinity for σ(A)-RNAP.

Analysis of bacterial RNase P RNA and protein interaction by a magnetic biosensor technique.

A magnetic sensor technique was applied to analyze the interaction of immobilized bacterial RNase P protein and 3'-biotinylated RNase P RNA bound to streptavidin-coated magnetic beads. Our measurements with three types of beads from different suppliers resulted in K(d) values of about 1-2 nM (at 4.5 mM Mg(2+) and 150 mM NH(4)(+)) for Escherichia coli RNase P RNA and protein, consistent with previous analyses using different techniques.