rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R
ABSTRACT RNase R is a highly processive, hydrolytic 3′-5′ exoribonuclease belonging to the RNB/RNR superfamily which plays significant roles in RNA metabolism in bacteria. The enzyme was observed to be essential for growth of the psychrophilic Antarctic bacterium Pseudomonas syringae Lz4W at a low t...
Published in: | Applied and Environmental Microbiology |
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American Society for Microbiology
2011
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Online Access: | http://dx.doi.org/10.1128/aem.05683-11 https://journals.asm.org/doi/pdf/10.1128/AEM.05683-11 |
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crasmicro:10.1128/aem.05683-11 2024-05-19T07:29:08+00:00 rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R Sulthana, Shaheen Rajyaguru, Purusharth I. Mittal, Pragya Ray, Malay K. 2011 http://dx.doi.org/10.1128/aem.05683-11 https://journals.asm.org/doi/pdf/10.1128/AEM.05683-11 en eng American Society for Microbiology https://journals.asm.org/non-commercial-tdm-license Applied and Environmental Microbiology volume 77, issue 22, page 7896-7904 ISSN 0099-2240 1098-5336 journal-article 2011 crasmicro https://doi.org/10.1128/aem.05683-11 2024-05-02T06:49:30Z ABSTRACT RNase R is a highly processive, hydrolytic 3′-5′ exoribonuclease belonging to the RNB/RNR superfamily which plays significant roles in RNA metabolism in bacteria. The enzyme was observed to be essential for growth of the psychrophilic Antarctic bacterium Pseudomonas syringae Lz4W at a low temperature. We present results here pertaining to the biochemical properties of RNase R and the RNase R-encoding gene ( rnr ) locus from this bacterium. By cloning and expressing a His 6 -tagged form of the P. syringae RNase R (RNase R Ps ), we show that the enzyme is active at 0 to 4°C but exhibits optimum activity at ∼25°C. The enzyme is heat labile in nature, losing activity upon incubation at 37°C and above, a hallmark of many psychrophilic enzymes. The enzyme requires divalent cations (Mg 2+ and Mn 2+ ) for activity, and the activity is higher in 50 to 150 mM KCl when it largely remains as a monomer. On synthetic substrates, RNase R Ps exhibited maximum activity on poly(A) and poly(U) in preference over poly(G) and poly(C). The enzyme also degraded structured malE-malF RNA substrates. Analysis of the cleavage products shows that the enzyme, apart from releasing 5′-nucleotide monophosphates by the processive exoribonuclease activity, produces four-nucleotide end products, as opposed to two-nucleotide products, of RNA chain by Escherichia coli RNase R. Interestingly, three ribonucleotides (ATP, GTP, and CTP) inhibited the activity of RNase R Ps in vitro . The ability of the nonhydrolyzable ATP-γS to inhibit RNase R Ps activity suggests that nucleotide hydrolysis is not required for inhibition. This is the first report on the biochemical property of a psychrophilic RNase R from any bacterium. Article in Journal/Newspaper Antarc* Antarctic ASM Journals (American Society for Microbiology) Applied and Environmental Microbiology 77 22 7896 7904 |
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crasmicro |
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English |
description |
ABSTRACT RNase R is a highly processive, hydrolytic 3′-5′ exoribonuclease belonging to the RNB/RNR superfamily which plays significant roles in RNA metabolism in bacteria. The enzyme was observed to be essential for growth of the psychrophilic Antarctic bacterium Pseudomonas syringae Lz4W at a low temperature. We present results here pertaining to the biochemical properties of RNase R and the RNase R-encoding gene ( rnr ) locus from this bacterium. By cloning and expressing a His 6 -tagged form of the P. syringae RNase R (RNase R Ps ), we show that the enzyme is active at 0 to 4°C but exhibits optimum activity at ∼25°C. The enzyme is heat labile in nature, losing activity upon incubation at 37°C and above, a hallmark of many psychrophilic enzymes. The enzyme requires divalent cations (Mg 2+ and Mn 2+ ) for activity, and the activity is higher in 50 to 150 mM KCl when it largely remains as a monomer. On synthetic substrates, RNase R Ps exhibited maximum activity on poly(A) and poly(U) in preference over poly(G) and poly(C). The enzyme also degraded structured malE-malF RNA substrates. Analysis of the cleavage products shows that the enzyme, apart from releasing 5′-nucleotide monophosphates by the processive exoribonuclease activity, produces four-nucleotide end products, as opposed to two-nucleotide products, of RNA chain by Escherichia coli RNase R. Interestingly, three ribonucleotides (ATP, GTP, and CTP) inhibited the activity of RNase R Ps in vitro . The ability of the nonhydrolyzable ATP-γS to inhibit RNase R Ps activity suggests that nucleotide hydrolysis is not required for inhibition. This is the first report on the biochemical property of a psychrophilic RNase R from any bacterium. |
format |
Article in Journal/Newspaper |
author |
Sulthana, Shaheen Rajyaguru, Purusharth I. Mittal, Pragya Ray, Malay K. |
spellingShingle |
Sulthana, Shaheen Rajyaguru, Purusharth I. Mittal, Pragya Ray, Malay K. rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R |
author_facet |
Sulthana, Shaheen Rajyaguru, Purusharth I. Mittal, Pragya Ray, Malay K. |
author_sort |
Sulthana, Shaheen |
title |
rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R |
title_short |
rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R |
title_full |
rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R |
title_fullStr |
rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R |
title_full_unstemmed |
rnr Gene from the Antarctic Bacterium Pseudomonas syringae Lz4W, Encoding a Psychrophilic RNase R |
title_sort |
rnr gene from the antarctic bacterium pseudomonas syringae lz4w, encoding a psychrophilic rnase r |
publisher |
American Society for Microbiology |
publishDate |
2011 |
url |
http://dx.doi.org/10.1128/aem.05683-11 https://journals.asm.org/doi/pdf/10.1128/AEM.05683-11 |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Applied and Environmental Microbiology volume 77, issue 22, page 7896-7904 ISSN 0099-2240 1098-5336 |
op_rights |
https://journals.asm.org/non-commercial-tdm-license |
op_doi |
https://doi.org/10.1128/aem.05683-11 |
container_title |
Applied and Environmental Microbiology |
container_volume |
77 |
container_issue |
22 |
container_start_page |
7896 |
op_container_end_page |
7904 |
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1799477703542308864 |