|PROSITE documentation PDOC51198 [for PROSITE entry PS51217]|
Helicases have been classified in 5 superfamilies (SF1-SF5) . All of the proteins bind ATP and, consequently, all of them carry the classical Walker A (phosphate-binding loop or P-loop) (see <PDOC00017>) and Walker B (Mg2+-binding aspartic acid) motifs . For the two largest groups, commonly referred to as SF1 and SF2, a total of seven characteristic motifs have been identified  which are distributed over two structural domains, an N-terminal ATP-binding domain and a C-terminal domain. UvrD-like DNA helicases belong to SF1, but they differ from classical SF1/SF2 (see <PDOC51192>) by a large insertion in each domain. UvrD-like DNA helicases unwind DNA with a 3'-5' polarity .
Crystal structures of several uvrD-like DNA helicases have been solved (see for example <PDB:1UAA>) [4,5,6]. They are monomeric enzymes consisting of two domains with a common α-β RecA-like core. The ATP-binding site is situated in a cleft between the N-terminus of the ATP-binding domain and the beginning of the C-terminal domain. The enzyme crystallizes in two different conformations (open and closed). The conformational difference between the two forms comprises a large rotation of the end of the C-terminal domain by approximately 130°. This "domain swiveling" was proposed to be an important aspect of the mechanism of the enzyme .
Some proteins that belong to the uvrD-like DNA helicase family are listed below:
To recognize uvrD-like DNA helicases we have developed two profiles. The first one recognizes the ATP-binding domain, whereas the second one is directed against the C-terminal domain.Last update:
June 2006 / First entry.
PROSITE methods (with tools and information) covered by this documentation:
|1||Authors||Gorbalenya A.E. and Koonin E.V. .|
|Title||Helicases: amino acid sequence comparisons and structure-function relationships.|
|Source||Curr. Opin. Struct. Biol. 3:419-429(1993).|
|2||Authors||Gorbalenya A.E. Koonin E.V. Donchenko A.P. Blinov V.M.|
|Title||Two related superfamilies of putative helicases involved in replication, recombination, repair and expression of DNA and RNA genomes.|
|Source||Nucleic Acids Res. 17:4713-4730(1989).|
|3||Authors||Soultanas P. Wigley D.B.|
|Title||DNA helicases: 'inching forward'.|
|Source||Curr. Opin. Struct. Biol. 10:124-128(2000).|
|4||Authors||Korolev S. Hsieh J. Gauss G.H. Lohman T.M. Waksman G.|
|Title||Major domain swiveling revealed by the crystal structures of complexes of E. coli Rep helicase bound to single-stranded DNA and ADP.|
|5||Authors||Velankar S.S. Soultanas P. Dillingham M.S. Subramanya H.S. Wigley D.B.|
|Title||Crystal structures of complexes of PcrA DNA helicase with a DNA substrate indicate an inchworm mechanism.|
|6||Authors||Singleton M.R. Dillingham M.S. Gaudier M. Kowalczykowski S.C. Wigley D.B.|
|Title||Crystal structure of RecBCD enzyme reveals a machine for processing DNA breaks.|