Polynucleotide phosphorylase
Oxford Dictionary of Biochemistry:
Top
polynucleotide phosphorylase
an alternative name for polyribonucleotide nucleotidyltransferase (EC 2.7.7.8).
| polynucleotide phosphatase, polynucleotide ligase, polynucleotide ligase | |
| polyol, polyol pathway, polyomavirus |
Wikipedia on Answers.com:
Top
Polynucleotide phosphorylase
| Polynucleotide Phosphorylase | |||||||
|---|---|---|---|---|---|---|---|
 |
|||||||
| Structure of the PNPase trimer from Streptomyces antibioticus. PDB 1e3p. [1] | |||||||
| Identifiers | |||||||
| EC number | 2.7.7.8 | ||||||
| CAS number | 9014-12-4 | ||||||
| Databases | |||||||
| IntEnz | IntEnz view | ||||||
| BRENDA | BRENDA entry | ||||||
| ExPASy | NiceZyme view | ||||||
| KEGG | KEGG entry | ||||||
| MetaCyc | metabolic pathway | ||||||
| PRIAM | profile | ||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||
| Gene Ontology | AmiGO / EGO | ||||||
|
|||||||
Polynucleotide Phosphorylase (PNPase) is a bifunctional enzyme with a phosphorolytic 3' to 5' exoribonuclease activity and a 3'-terminal oligonucleotide polymerase activity.[2] It is involved on mRNA processing and degradation in bacteria, plants,[3] and in humans.[4]
In humans, the enzyme is encoded by the PNPT1 gene. In its active form, the protein forms a ring structure consisting of three PNPase molecules. Each PNPase molecule consists of two RNase PH domains, an S1 RNA binding domain and an K-homology domain. The protein is present in bacteria and in the chloroplasts[2] and mitochondria[5] of some eukaryotic cells. In eukaryotes and archaea, a structurally and evolutionary related complex exists, called the exosome.[5]
The same abbreviation (PNPase) is also used for another, otherwise unrelated enzyme, Purine nucleoside phosphorylase.
Model organisms
| Characteristic | Phenotype |
|---|---|
| Homozygote viability | Abnormal |
| Recessive lethal study | Abnormal |
| Fertility | Normal |
| Body weight | Normal |
| Anxiety | Normal |
| Neurological assessment | Normal |
| Grip strength | Normal |
| Hot plate | Normal |
| Dysmorphology | Normal |
| Indirect calorimetry | Normal |
| Glucose tolerance test | Normal |
| Auditory brainstem response | Normal |
| DEXA | Normal |
| Radiography | Normal |
| Body temperature | Normal |
| Eye morphology | Normal |
| Clinical chemistry | Normal |
| Plasma immunoglobulins | Normal |
| Haematology | Normal |
| Peripheral blood lymphocytes | Normal |
| Micronucleus test | Normal |
| Heart weight | Normal |
| Skin Histopathology | Normal |
| Brain histopathology | Normal |
| Salmonella infection | Normal[6] |
| Citrobacter infection | Normal[7] |
| All tests and analysis from[8][9] |
Model organisms have been used in the study of PNPT1 function. A conditional knockout mouse line, called Pnpt1tm1a(KOMP)Wtsi[10][11] was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.[12][13][14]
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion.[8][15] Twenty six tests were carried out on mutant mice and two significant abnormalities were observed.[8] No homozygous mutant embryos were identified during gestation, and therefore none survived until weaning. The remaining tests were carried out on heterozygous mutant adult mice; no additional significant abnormalities were observed in these animals.[8]
| Human PNPase I | |
|---|---|
| Identifiers | |
| Symbol | PNPASE |
| Alt. symbols | PNPase, OLD35, old-35 |
| Entrez | 87178 |
| HUGO | 23166 |
| OMIM | 610316 |
| PDB | 1E3P |
| RefSeq | NM_033109 |
| UniProt | Q8TCS8 |
| Other data | |
| EC number | 2.7.7.8 |
| Locus | Chr. 2 p15 |
References
- ^ {{Symmons, M. F.; Jones, G. H.; Luisi, B. F. (2000). "A duplicated fold is the structural basis for polynucleotide phosphorylase catalytic activity, processivity, and regulation". Structure (London, England : 1993) 8 (11): 1215–1226. DOI:10.1016/S0969-2126(00)00521-9. PMID 11080643.
- ^ a b Yehudai-Resheff S, Hirsh M, Schuster G (2001). "Polynucleotide phosphorylase functions as both an exonuclease and a poly(A) polymerase in spinach chloroplasts". Mol. Cell. Biol. 21 (16): 5408–16. DOI:10.1128/MCB.21.16.5408-5416.2001. PMC 87263. PMID 11463823. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=87263.
- ^ Yehudai-Resheff S, Zimmer SL, Komine Y, Stern DB (2007). "Integration of chloroplast nucleic acid metabolism into the phosphate deprivation response in Chlamydomonas reinhardtii". Plant Cell 19 (3): 1023–38. DOI:10.1105/tpc.106.045427. PMC 1867357. PMID 17351118. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1867357.
- ^ Sarkar D, Fisher PB (2006). "Human polynucleotide phosphorylase (hPNPase old-35): an RNA degradation enzyme with pleiotrophic biological effects". Cell Cycle 5 (10): 1080–4. PMID 16687933. http://www.landesbioscience.com/journals/cc/article/sarkarCC5-10.pdf.
- ^ a b Schilders G, van Dijk E, Raijmakers R, Pruijn GJ (2006). "Cell and molecular biology of the exosome: how to make or break an RNA". Int. Rev. Cytol. 251: 159–208. DOI:10.1016/S0074-7696(06)51005-8. PMID 16939780.
- ^ "Salmonella infection data for Pnpt1". Wellcome Trust Sanger Institute. http://www.sanger.ac.uk/mouseportal/phenotyping/MBDU/salmonella-challenge/.
- ^ "Citrobacter infection data for Pnpt1". Wellcome Trust Sanger Institute. http://www.sanger.ac.uk/mouseportal/phenotyping/MBDU/citrobacter-challenge/.
- ^ a b c d Gerdin AK (2010). "The Sanger Mouse Genetics Programme: High throughput characterisation of knockout mice". Acta Ophthalmologica 88: 925–7. DOI:10.1111/j.1755-3768.2010.4142.x.
- ^ Mouse Resources Portal, Wellcome Trust Sanger Institute.
- ^ "International Knockout Mouse Consortium". http://www.knockoutmouse.org/martsearch/search?query=Pnpt1.
- ^ "Mouse Genome Informatics". http://www.informatics.jax.org/searchtool/Search.do?query=MGI:4364657.
- ^ Skarnes, W. C.; Rosen, B.; West, A. P.; Koutsourakis, M.; Bushell, W.; Iyer, V.; Mujica, A. O.; Thomas, M. et al. (2011). "A conditional knockout resource for the genome-wide study of mouse gene function". Nature 474 (7351): 337–342. DOI:10.1038/nature10163. PMID 21677750.
- ^ Dolgin E (2011). "Mouse library set to be knockout". Nature 474 (7351): 262–3. DOI:10.1038/474262a. PMID 21677718.
- ^ Collins FS, Rossant J, Wurst W (2007). "A Mouse for All Reasons". Cell 128 (1): 9–13. DOI:10.1016/j.cell.2006.12.018. PMID 17218247.
- ^ van der Weyden L, White JK, Adams DJ, Logan DW (2011). "The mouse genetics toolkit: revealing function and mechanism.". Genome Biol 12 (6): 224. DOI:10.1186/gb-2011-12-6-224. PMC 3218837. PMID 21722353. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3218837.
External links
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| This transferase article is a stub. You can help Wikipedia by expanding it. |
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Post a question - any question - to the WikiAnswers community:
Copyrights:
Oxford Dictionary of Biochemistry
Oxford University Press. Oxford Dictionary of Biochemistry and Molecular Biology © 1997, 2000, 2006 All rights reserved.
Read more
