Limits...
YtqI from Bacillus subtilis has both oligoribonuclease and pAp-phosphatase activity.

Mechold U, Fang G, Ngo S, Ogryzko V, Danchin A - Nucleic Acids Res. (2007)

Bottom Line: Firmicutes including Bacillus subtilis do not have an Oligoribonuclease (Orn) homologous protein and it is not yet understood which proteins accomplish the equivalent function in these organisms.An ytqI mutant in B. subtilis shows impairment of growth in the absence of cysteine, a phenotype resembling that of a cysQ mutant in E. coli.Phylogenetic distribution of YtqI, Orn and CysQ supports bifunctionality of YtqI.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur, URA 2171, Unité de Génétique des Génomes Bactériens, 75724 Paris Cedex 15, France. umechold@pasteur.fr

ABSTRACT
Oligoribonuclease is the only RNase in Escherichia coli that is able to degrade RNA oligonucleotides five residues and shorter in length. Firmicutes including Bacillus subtilis do not have an Oligoribonuclease (Orn) homologous protein and it is not yet understood which proteins accomplish the equivalent function in these organisms. We had previously identified oligoribonucleases Orn from E. coli and its human homolog Sfn in a screen for proteins that are regulated by 3'-phosphoadenosine 5'-phosphate (pAp). Here, we identify YtqI as a potential functional analog of Orn through its interaction with pAp. YtqI degrades RNA oligonucleotides in vitro with preference for 3-mers. In addition, YtqI has pAp-phosphatase activity in vitro. In agreement with these data, YtqI is able to complement both orn and cysQ mutants in E. coli. An ytqI mutant in B. subtilis shows impairment of growth in the absence of cysteine, a phenotype resembling that of a cysQ mutant in E. coli. Phylogenetic distribution of YtqI, Orn and CysQ supports bifunctionality of YtqI.

Show MeSH

Related in: MedlinePlus

Activity of YtqI on RNA 24-mers. Reactions containing 5′ 33P-labeled RNA 24-mers (5′CACACACACACACACACACACACA3′) were incubated for 30 min at 37°C. M, decade marker; 1, no enzyme control; 2, YtqI; 3, positive control (YhaM).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1935014&req=5

Figure 6: Activity of YtqI on RNA 24-mers. Reactions containing 5′ 33P-labeled RNA 24-mers (5′CACACACACACACACACACACACA3′) were incubated for 30 min at 37°C. M, decade marker; 1, no enzyme control; 2, YtqI; 3, positive control (YhaM).

Mentions: In order to ask whether YtqI degrades specifically nanoRNA or is active on longer substrates as well, we tested degradation of a RNA 24-mer 5′-end labeled with 33P. Figure 6 shows that activity of YtqI on this substrate was insignificant. The YtqI-catalyzed turnover of 24-mers into monomers could be roughly estimated from this experiment as 0.01 pmol/μg/min.Figure 6.


YtqI from Bacillus subtilis has both oligoribonuclease and pAp-phosphatase activity.

Mechold U, Fang G, Ngo S, Ogryzko V, Danchin A - Nucleic Acids Res. (2007)

Activity of YtqI on RNA 24-mers. Reactions containing 5′ 33P-labeled RNA 24-mers (5′CACACACACACACACACACACACA3′) were incubated for 30 min at 37°C. M, decade marker; 1, no enzyme control; 2, YtqI; 3, positive control (YhaM).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1935014&req=5

Figure 6: Activity of YtqI on RNA 24-mers. Reactions containing 5′ 33P-labeled RNA 24-mers (5′CACACACACACACACACACACACA3′) were incubated for 30 min at 37°C. M, decade marker; 1, no enzyme control; 2, YtqI; 3, positive control (YhaM).
Mentions: In order to ask whether YtqI degrades specifically nanoRNA or is active on longer substrates as well, we tested degradation of a RNA 24-mer 5′-end labeled with 33P. Figure 6 shows that activity of YtqI on this substrate was insignificant. The YtqI-catalyzed turnover of 24-mers into monomers could be roughly estimated from this experiment as 0.01 pmol/μg/min.Figure 6.

Bottom Line: Firmicutes including Bacillus subtilis do not have an Oligoribonuclease (Orn) homologous protein and it is not yet understood which proteins accomplish the equivalent function in these organisms.An ytqI mutant in B. subtilis shows impairment of growth in the absence of cysteine, a phenotype resembling that of a cysQ mutant in E. coli.Phylogenetic distribution of YtqI, Orn and CysQ supports bifunctionality of YtqI.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur, URA 2171, Unité de Génétique des Génomes Bactériens, 75724 Paris Cedex 15, France. umechold@pasteur.fr

ABSTRACT
Oligoribonuclease is the only RNase in Escherichia coli that is able to degrade RNA oligonucleotides five residues and shorter in length. Firmicutes including Bacillus subtilis do not have an Oligoribonuclease (Orn) homologous protein and it is not yet understood which proteins accomplish the equivalent function in these organisms. We had previously identified oligoribonucleases Orn from E. coli and its human homolog Sfn in a screen for proteins that are regulated by 3'-phosphoadenosine 5'-phosphate (pAp). Here, we identify YtqI as a potential functional analog of Orn through its interaction with pAp. YtqI degrades RNA oligonucleotides in vitro with preference for 3-mers. In addition, YtqI has pAp-phosphatase activity in vitro. In agreement with these data, YtqI is able to complement both orn and cysQ mutants in E. coli. An ytqI mutant in B. subtilis shows impairment of growth in the absence of cysteine, a phenotype resembling that of a cysQ mutant in E. coli. Phylogenetic distribution of YtqI, Orn and CysQ supports bifunctionality of YtqI.

Show MeSH
Related in: MedlinePlus