Is crab duplex-specific nuclease a member of the Serratia family of non-specific nucleases?
Kamchatka crab duplex-specific nuclease (Par_DSN) has been classified as a member of the family of DNA/RNA non-specific beta-beta-alpha metal finger (bba-Me-finger) nucleases, the archetype of which is the nuclease from Serratia marcescens. Although the enzyme under investigation seems to belong to the family of S. marcescens nucleases, Par_DSN exhibits a marked preference for double-stranded DNA as a substrate and this property is unusual for other members of this family. We have searched other Arthropod species and identified a number of novel Par_DSN homologs. A phylogenetic analysis demonstrates that the Par_DSN-like enzymes constitute a separate branch in the evolutionary tree of bba-Me-finger nucleases. Combining sequence analysis and site-directed mutagenesis, we found that Par_DSN and its homologs possess the nuclease domain that is slightly longer than that of classic Serratia relatives. The active site composition of Par_DSN is similar but not identical to that of classic Serratia nucleases. Based on these findings, we proposed a new classification of Par_DSN-like nucleases.
Shemiakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Miklukho-Maklaya 16/10, 117871 Moscow, Russia.
Veronika E
VE
Anisimova
Alex S
AS
Shcheglov
Ekaterina A
EA
Bogdanova
Denis V
DV
Rebrikov
Alexey N
AN
Nekrasov
Ekaterina V
EV
Barsova
Dmitry A
DA
Shagin
Sergey A
SA
Lukyanov
D000818:Animals; D001665:Binding Sites; D003386:Brachyura / Q000201:enzymology*; D003851:Deoxyribonucleases / Q000737:chemistry* / Q000145:classification*; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012705:Serratia / Q000201:enzymology*
D003851:Deoxyribonucleases