Gd. Small et al., CHARACTERIZATION OF A CHLAMYDOMONAS-REINHARDTII GENE ENCODING A PROTEIN OF THE DNA PHOTOLYASE BLUE-LIGHT PHOTORECEPTOR FAMILY, Plant molecular biology, 28(3), 1995, pp. 443-454
The organization and nucleotide sequence of a gene from Chlamydomonas
reinhardtii encoding a member of the DNA photolyase/blue light photore
ceptor protein family is reported. A region of over 7 kb encompassing
the gene was sequenced. Northern analysis detected a single 4.2 kb mRN
A. The gene consists of eight exons and seven introns, and encodes a p
redicted protein of 867 amino acids. The first 500 amino acids exhibit
significant homology with previously sequenced DNA photolyases, showi
ng the closest relationship to mustard (Sinapis alba) photolyase (43%
identity). An even higher identity, 49%, is obtained when the Chlamydo
monas gene product is compared to the putative blue-light photorecepto
r (HY4) from Arabidopsis thaliana. Both the Chlamydomonas and the Arab
idopsis proteins differ from the well characterized DNA photolyases in
that they contain a carboxyl terminal extension of 367 and 181 amino
acids, respectively. However, there is very little homology between th
e carboxyl terminal domains of the two proteins. A previously isolated
Chlamydomonas mutant, phr1, which is deficient in DNA photolyase acti
vity, especially in the nucleus, was shown by RFLP analysis not to be
linked to the gene we have isolated. We propose this gene encodes a ca
ndidate Chlamydomonas blue light photoreceptor.