Open AccessA novel restriction–modification system from Xanthomonas campestris pv. vesicatoria encodes a m4C‐methyltransferase and a nonfunctional restriction endonuclease
Author(s) -
Yu YuJen,
Yang MingTe
Publication year - 2007
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2007.00738.x
Subject(s) - restriction enzyme , biology , genetics , open reading frame , recognition sequence , gene , microbiology and biotechnology , restriction map , endonuclease , peptide sequence , plasmid , restriction site
A novel restriction–modification (R–M) system, designated as xveIIRM , from chromosomal DNA of the Xanthomonas campestris pv. vesicatoria strain 7‐1 (Xcv7‐1) was cloned and characterized. The xveIIRM genes involved in this R–M system are aligned in a tail‐to‐tail orientation and overlapped by 12 base pairs. XveII methyltransferase gene could encode a 299‐amino acid protein (M.XveII) with an estimated mass of 33.7 kDa and was classified to be a member of β‐class of m4C‐MTase. M.XveII methylates the second cytosine of the 5′‐CCCGGG‐3′ recognition sequence. The predicted amino acid sequence of the intact XveII endonuclease shared 41.9% identity with SmaI. However, a premature TAA translation termination codon was found in the open reading frame of xveIIR and expected to encode an 18.3 kDa truncated protein. The sequence data are consistent with observation of this study that no SmaI‐like restriction activity could be detected in the cell extract of Xcv7‐1.