Bacillus subtilis ribonucleases J1 and J2 form a complex with altered enzyme behaviour.
Ribonucleases J1 and J2 are recently discovered enzymes with dual 5'-to-3' exoribonucleolytic/endoribonucleolytic activity that plays a key role in the maturation and degradation of Bacillus subtilis RNAs. RNase J1 is essential, while its paralogue RNase J2 is not. Up to now, it had generally been assumed that the two enzymes functioned independently. Here we present evidence that RNases J1 and J2 form a complex that is likely to be the predominant form of these enzymes in wild-type cells. While both RNase J1 and the RNase J1/J2 complex have robust 5'-to-3' exoribonuclease activity in vitro, RNase J2 has at least two orders of magnitude weaker exonuclease activity, providing a possible explanation for why RNase J1 is essential. The association of the two proteins also has an effect on the endoribonucleolytic properties of RNases J1 and J2. While the individual enzymes have similar endonucleolytic cleavage activities and specificities, as a complex they behave synergistically to alter cleavage site preference and to increase cleavage efficiency at specific sites. These observations dramatically change our perception of how these ribonucleases function and provide an interesting example of enzyme subfunctionalization after gene duplication.
Mathy
Nathalie
N
CNRS UPR 9073 (affiliated with Université de Paris 7-Denis Diderot), Paris, France.
Hébert
Agnès
A
Mervelet
Peggy
P
Bénard
Lionel
L
Dorléans
Audrey
A
Li de la Sierra-Gallay
Inés
I
Noirot
Philippe
P
Putzer
Harald
H
Condon
Ciarán
C
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D020440:Gene Duplication; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D007700:Kinetics; D046911:Macromolecular Substances / Q000737:chemistry / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D011485:Protein Binding; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012260:Ribonucleases / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
D046911:Macromolecular Substances; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012260:Ribonucleases