Spore photoproduct lyase (EC 4.1.99.14, SAM, SP lyase, SPL, SplB, SplG) is a radical SAM enzyme that repairs DNA cross linking of thymine bases caused by UV-radiation. There are several types of thymine cross linking, but SPL specifically targets 5-thyminyl-5,6-dihydrothymine, which is also called spore photoproduct (SP) [1] [2]. Spore photoproduct is the predominant type of thymine crosslinking in germinating endospores, which is why SPL is unique to organisms that produce endospores. Other types of thymine crosslinking, such as cyclobutane pyrimidine dimers (CPD) and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs), are less commonly formed in endospores. These differences in DNA crosslinking are a function of differing DNA structure. Spore genomic DNA features many DNA binding proteins called small acid soluble proteins [3], which changes the DNA from the traditional B-form conformation to an A-from conformation [4] [5]. This difference in conformation is believed to be the reason why spores predominantly produce SP in response to UV-radiation [6] [7] [8].
The repair mechanism utilizing spore photoproduct lyase is one of the reasons for the resilience of certain bacterial spores. Through a series of radical reactions the photodimer, 3 5-thyminyl-5,6-dihydrothymine, is disconnected to give back two functional thymine rings.[9][10]
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Spore photoproduct lyase is part of one of two main pathways which are used to repair cross linked 5-thyminyl-5,6-dihydrothymine caused by UV radiation: the spore-specific DNA repair system (which utilizes spore photoproduct lyase), and the general nucleotide excision repair pathway (NER). [11]
| Spore photoproduct lyase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 4.1.99.14 | ||||||||
| CAS no. | 37290-70-3 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
References
edit- ^ Moeller, Ralf (January 2007). "UV-radiation-induced formation of DNA bipyrimidine photoproducts in Bacillus subtilis endospores and their repair during germination" (PDF). International Microbiology: 8. doi:10.2436/20.1501.01.6. PMID 17407059.
- ^ Munakata, Nobuo (April 1972). "Genetically controlled removal of "spore photoproduct" from deoxyribonucleic acid of ultraviolet-irradiated Bacillus subtilis spores" (PDF). Journal of Bacteriology. 111. PMID 4204907.
- ^ Setlow, Peter (1988). "Small, acid-soluble spore proteins of Bacillus species: structure, synthesis, genetics, function, and degradation". Annual Reviews Microbiology. 42. doi:10.1146/annurev.mi.42.100188.001535.
- ^ Nicholoson, W (October 1991). "Ultraviolet irradiation of DNA complexed with alpha/beta-type small, acid-soluble proteins from spores of Bacillus or Clostridium species makes spore photoproduct but not thymine dimers". Proceedings of the National Academy of Sciences of the United States of America. doi:10.1073/pnas.88.19.8288. PMID 1924287.
- ^ Mohr, S (Jan 1991). "Binding of small acid-soluble spore proteins from Bacillus subtilis changes the conformation of DNA from B to A." Proceedings of the National Academy of Sciences of the United States of America. doi:10.1073/pnas.88.1.77. PMID 1898779.
- ^ Moeller, Ralf (January 2007). "UV-radiation-induced formation of DNA bipyrimidine photoproducts in Bacillus subtilis endospores and their repair during germination" (PDF). International Microbiology: 8. doi:10.2436/20.1501.01.6. PMID 17407059.
- ^ Nicholoson, W (October 1991). "Ultraviolet irradiation of DNA complexed with alpha/beta-type small, acid-soluble proteins from spores of Bacillus or Clostridium species makes spore photoproduct but not thymine dimers". Proceedings of the National Academy of Sciences of the United States of America. doi:10.1073/pnas.88.19.8288. PMID 1924287.
- ^ Mohr, S (Jan 1991). "Binding of small acid-soluble spore proteins from Bacillus subtilis changes the conformation of DNA from B to A." Proceedings of the National Academy of Sciences of the United States of America. doi:10.1073/pnas.88.1.77. PMID 1898779.
- ^ Wang SC, Frey PA (March 2007). "S-adenosylmethionine as an oxidant: the radical SAM superfamily". Trends in Biochemical Sciences. 32 (3): 101–10. doi:10.1016/j.tibs.2007.01.002. PMID 17291766.Note that the SPL drawings are incorrect in this paper and the erratum
- ^ Buis JM, Cheek J, Kalliri E, Broderick JB (September 2006). "Characterization of an active spore photoproduct lyase, a DNA repair enzyme in the radical S-adenosylmethionine superfamily". The Journal of Biological Chemistry. 281 (36): 25994–6003. doi:10.1074/jbc.M603931200. PMID 16829680.
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External links
edit- Spore+photoproduct+lyase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
External links
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