Table 1.

Presence of Photolyase Genes in the Main Groups of Organisms

Taxon	Class Ia	Class II	(6-4) Photolyases	Prokaryote Groupb	Single Strand
Bacteria
Acidobacteria		+
Actinobacteria	+	+
α-Proteobacteria	+	+		+	+
Bacteroidetes	+	+		+	+
β-Proteobacteria	+			+	+
Cyanobacteria	+	+	+c	+	+
Chlamydiae				+
Chlorobi		+
Chloroflexi	+
δ-Proteobacteria	+	+
ε-Proteobacteria	+
Firmicutes	+			+
γ-Proteobacteria	+			+	+
Planctomycetes		+			+
Spirochaeta		+
Thermotogae	+
Archaea
Crenarcheota	+
Euryarchaeota	+	+		+	+
Eukarya
Chromalveolata	+	+	+		+
Excavatad	+	?	?		?
Opisthokonta	+	+	+		+
Plantae	+	+	+		+
Virus
Poxviridae		+
Baculoviridae		+

^aIncludes plant cryptochromes and related sequences. See text.

^bPutative orthologs of (6-4) photolyases.

^cA (6-4) photolyase-like gene is exceptionally found in the genome of the cyanobacteria Gloeobacter violaceous (glr1749), probably as a result of horizontal gene transfer from green algae.

^dIn addition to CPD class I photolyases, some species from Trypanosomatidae have another photolyase homolog of uncertain origin.