Cyclobutane pyrimidine dimer

Climate change and ozone depletion have caused increased ultraviolet B (UVB; 280-315nm) radiation levels on earth, which has been predicted to cause decreased growth and yield of various crops, including rice, the most important staple food worldwide. UVB radiation sensitivity varies extensively in Asian rice (Oryza sativa L.) and African rice (Oryza glaberrima Steud. and Oryza barthii A. Chev.) cultivars, and the activity of cyclobutane pyrimidine dimer (CPD) photolyase that repairs UVB-induced CPD is an essential factor underlying UVB sensitivity in rice.

12p lyhuyenthu 31-01-2023 6 2   Download

Cyclobutane-type pyrimidine dimers generated by ultraviolet irradiation of DNA can be cleaved by DNA photolyase. The enzyme-catalysed reaction is believed to be initiated by the light-induced transfer of an electron from the anionic FADH ) chromophore of the enzyme to the pyrimidine dimer. In this contribution, first infrared experiments using a novel E109A mutant ofEscherichia coliDNA photolyase, which is catalytically active but unable to bind the second cofactor methenyltetrahydrofolate, are described....

0p awards 06-04-2013 27 1   Download

Photolyase is a light-dependent enzyme that repairs pyrimidine dimers in DNA. Two types of photolyases have been found in frogXenopus laevis, one for repairing cyclobutane pyrimidine dimers (CPD photolyase) and the other for pyrimidine–pyrimidone (6–4)photoproduct [(6–4)photolyase]. However, little is known about the former type of theXenopusphotolyases.

11p dell39 27-03-2013 47 2   Download