Structure of the N-terminal fragment of topoisomerase V reveals a new family of topoisomerases.
Topoisomerases are involved in controlling and maintaining the topology of DNA and are present in all kingdoms of life. Unlike all other types of topoisomerases, similar type IB enzymes have only been identified in bacteria and eukarya. The only putative type IB topoisomerase in archaea is represented by Methanopyrus kandleri topoisomerase V. Despite several common functional characteristics, topoisomerase V shows no sequence similarity to other members of the same type. The structure of the 61 kDa N-terminal fragment of topoisomerase V reveals no structural similarity to other topoisomerases. Furthermore, the structure of the active site region is different, suggesting no conservation in the cleavage and religation mechanism. Additionally, the active site is buried, indicating the need of a conformational change for activity. The presence of a topoisomerase in archaea with a unique structure suggests the evolution of a separate mechanism to alter DNA.
Taneja
Bhupesh
B
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, IL 60208-3500, USA.
Patel
Asmita
A
Slesarev
Alexei
A
Mondragón
Alfonso
A
D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D003461:Crystallography; D004264:DNA Topoisomerases, Type I / Q000737:chemistry* / Q000235:genetics; D019605:Euryarchaeota / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011487:Protein Conformation; D017422:Sequence Analysis, DNA; D013050:Spectrometry, Fluorescence
C082698:DNA topoisomerase V; D004264:DNA Topoisomerases, Type I