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Rehman MT, Dey P, Hassan MI, Ahmad F, Batra JK. Functional role of glutamine 28 and arginine 39 in double stranded RNA cleavage by human pancreatic ribonuclease. PLoS One 2011; 6:e17159. [PMID: 21408145 PMCID: PMC3050822 DOI: 10.1371/journal.pone.0017159] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 01/21/2011] [Indexed: 12/05/2022] Open
Abstract
Human pancreatic ribonuclease (HPR), a member of RNase A superfamily, has a high activity on double stranded (ds) RNA. By virtue of this activity HPR appears to be involved in the host-defense against pathogenic viruses. To delineate the mechanism of dsRNA cleavage by HPR, we have investigated the role of glutamine 28 and arginine 39 of HPR in its activity on dsRNA. A non-basic residue glycine 38, earlier shown to be important for dsRNA cleavage by HPR was also included in the study in the context of glutamine 28 and arginine 39. Nine variants of HPR respectively containing Q28A, Q28L, R39A, G38D, Q28A/R39A, Q28L/R39A, Q28A/G38D, R39A/G38D and Q28A/G38D/R39A mutations were generated and functionally characterized. The far-UV CD-spectral analysis revealed all variants, except R39A, to have structures similar to that of HPR. The catalytic activity of all HPR variants on single stranded RNA substrate was similar to that of HPR, whereas on dsRNA, the catalytic efficiency of all single residue variants, except for the Q28L, was significantly reduced. The dsRNA cleavage activity of R39A/G38D and Q28A/G38D/R39A variants was most drastically reduced to 4% of that of HPR. The variants having reduced dsRNA cleavage activity also had reduction in their dsDNA melting activity and thermal stability. Our results indicate that in HPR both glutamine 28 and arginine 39 are important for the cleavage of dsRNA. Although these residues are not directly involved in catalysis, both arginine 39 and glutamine 28 appear to be facilitating a productive substrate-enzyme interaction during the dsRNA cleavage by HPR.
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Affiliation(s)
- Md. Tabish Rehman
- Centre for Interdisciplinary Research in Basic Sciences, New Delhi, India
| | - Punyatirtha Dey
- Immunochemistry Laboratory, National Institute of Immunology, New Delhi, India
| | | | - Faizan Ahmad
- Centre for Interdisciplinary Research in Basic Sciences, New Delhi, India
| | - Janendra K. Batra
- Immunochemistry Laboratory, National Institute of Immunology, New Delhi, India
- * E-mail:
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Luft JR, Furlani NM, NeMoyer RE, Penna EJ, Wolfley JR, Snell ME, Potter SA, Snell EH. Crystal cookery - using high-throughput technologies and the grocery store as a teaching tool. J Appl Crystallogr 2010; 43:1189-1207. [PMID: 22184476 PMCID: PMC3238385 DOI: 10.1107/s0021889810027640] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 07/12/2010] [Indexed: 11/16/2022] Open
Abstract
Crystallography is a multidisciplinary field that links divergent areas of mathematics, science and engineering to provide knowledge of life on an atomic scale. Crystal growth, a key component of the field, is an ideal vehicle for education. Crystallization has been used with a 'grocery store chemistry' approach and linked to high-throughput remote-access screening technologies. This approach provides an educational opportunity that can effectively teach the scientific method, readily accommodate different levels of educational experience, and reach any student with access to a grocery store, a post office and the internet. This paper describes the formation of the program through the students who helped develop and prototype the procedures. A summary is presented of the analysis and preliminary results and a description given of how the program could be linked with other aspects of crystallography. This approach has the potential to bridge the gap between students in remote locations and with limited funding, and access to scientific resources, providing students with an international-level research experience.
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Affiliation(s)
- Joseph R. Luft
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
- Department of Structural and Computational Biology, SUNY Buffalo, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - Nicholas M. Furlani
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
- Case Western Reserve University, Cleveland, OH 44106, USA
| | - Rachel E. NeMoyer
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
- Pennsylvania State University, University Park, PA 16802, USA
| | - Elliott J. Penna
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
- Lehigh University, Bethlehem, PA 18015, USA
| | - Jennifer R. Wolfley
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - M. Elizabeth Snell
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - Stephen A. Potter
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
| | - Edward H. Snell
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA
- Department of Structural and Computational Biology, SUNY Buffalo, 700 Ellicott Street, Buffalo, NY 14203, USA
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