Effect of expression of M.HpyAVIB, a C5 cytosine methyltransferase on the E. coli BL21 (DE3) transcriptome

Helicobacter pylori genome is rich in restriction - modification (R-M) systems. Around 4 % of the genome codes for components of R-M systems. hpyAVIBM, which codes for a putative phase-variable C5 - cytosine methyltransferase (MTase) from H. pylori lacks a cognate restriction enzyme. To analysis the effect of expression of hpyAVIBM on the E. coli transcriptome, microarray analysis was done with the cells expressing wild type MTase with the cells expressing catalytic inactive mutant of the MTase.