Nwankwo DO, Lynch JJ, Moran LS, Fomenkov A, Slatko BE. The XmnI restriction-modification system: cloning, expression, sequence organization and similarity between the R and M genes.
Gene X 1996;
173:121-7. [PMID:
8964488 DOI:
10.1016/0378-1119(96)00062-5]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The xmnIRM genes from Xanthomonas manihotis 7AS1 have been cloned and expressed in Escherichia coli. The nucleotide (nt) sequences of both genes were determined. The XmnI methyltransferase (MTase)-encoding gene is 1861 bp in length and codes for 620 amino acids (aa) (68660 Da). The restriction endonuclease (ENase)-encoding gene is 959 bp long and therefore codes for a 319-aa protein (35275 Da). The two genes are aligned tail to tail and they overlap at their respective stop codons About 4 x 10(4) units/g wet cell paste of R.XmnI was obtained following IPTG induction in a suitable E. coli host. The xmnIR gene is expressed from the T7 promoter. M.XmnI probably modifies the first A in the sequence, GAA(N)4TTC. The xmnIR and M genes contain regions of conserved similarity and probably evolved from a common ancestor. M.XmnI is loosely related to M.EcoRI. The XmnI R-M system and the type-I R-M systems probably derived from a common ancestor.
Collapse