Table 1.

Results of in silico and in vitro screening of restriction enzymes in P.abyssi and P.horikoshii

Left part (columns 1–4): Candidate modification enzyme genes were sought by bioinformatics methods in the published genome sequences of P.abyssi and P.horikoshii.

Right part (columns 5–8): ORFs that neighbored one of the modification enzyme gene candidates and were annotated as unknown were selected as candidates for restriction enzyme genes. The restriction enzyme activities of their products were assayed on lambda DNA after their expression in a wheat-germ cell-free protein synthesis system.

The restriction gene candidates in the gray boxes were selected for the first round of screening, while the remainder were used in the second round. Those restriction genes in bold fonts (PAB0105, PH0583) were found to be active.

^aListed as a putative modification gene in REBASE.

^bHit by keyword searching in GTOP.

^cAssociated with a putative genome rearrangement (7).

^dProtein expression in the wheat-germ cell-free system as detected by SDS–PAGE and CBB (Coomassie Brilliant blue) staining.

^eLambda DNA was cleaved by the putative restriction enzyme.

^g‘CGAT’ indicates ‘based on CGAT’ (32).

^f‘NT’ indicates not tested.