Characterization of type II and III restriction-modification systems from Bacillus cereus strains ATCC 10987 and ATCC 14579.
The genomes of two Bacillus cereus strains (ATCC 10987 and ATCC 14579) have been sequenced. Here, we report the specificities of type II/III restriction (R) and modification (M) enzymes. Found in the ATCC 10987 strain, BceSI is a restriction endonuclease (REase) with the recognition and cut site CGAAG 24-25/27-28. BceSII is an isoschizomer of AvaII (G/GWCC). BceSIII cleaves at ACGGC 12/14. The BceSIII C terminus resembles the catalytic domains of AlwI, MlyI, and Nt.BstNBI. BceSIV is composed of two subunits and cleaves on both sides of GCWGC. BceSIV activity is strongly stimulated by the addition of cofactor ATP or GTP. The large subunit (R1) of BceSIV contains conserved motifs of NTPases and DNA helicases. The R1 subunit has no endonuclease activity by itself; it strongly stimulates REase activity when in complex with the R2 subunit. BceSIV was demonstrated to hydrolyze GTP and ATP in vitro. BceSIV is similar to CglI (GCSGC), and homologs of R1 are found in 11 sequenced bacterial genomes, where they are paired with specificity subunits. In addition, homologs of the BceSIV R1-R2 fusion are found in many sequenced microbial genomes. An orphan methylase, M.BceSV, was found to modify GCNGC, GGCC, CCGG, GGNNCC, and GCGC sites. A ParB-methylase fusion protein appears to nick DNA nonspecifically. The ATCC 14579 genome encodes an active enzyme Bce14579I (GCWGC). BceSIV and Bce14579I belong to the phospholipase D (PLD) family of endonucleases that are widely distributed among Bacteria and Archaea. A survey of type II and III restriction-modification (R-M) system genes is presented from sequenced B. cereus, Bacillus anthracis, and Bacillus thuringiensis strains.
New England Biolabs, Inc., Ipswich, Massachusetts, USA. xus@neb.com
Shuang-yong
SY
Xu
Rebecca L
RL
Nugent
Julie
J
Kasamkattil
Alexey
A
Fomenkov
Yogesh
Y
Gupta
Aneel
A
Aggarwal
Xiaolong
X
Wang
Zhiru
Z
Li
Yu
Y
Zheng
Richard
R
Morgan
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics / Q000378:metabolism*; D015263:Deoxyribonucleases, Type III Site-Specific / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D016680:Genome, Bacterial; D006160:Guanosine Triphosphate / Q000378:metabolism; D008969:Molecular Sequence Data; D021122:Protein Subunits
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D021122:Protein Subunits; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D015252:Deoxyribonucleases, Type II Site-Specific; D015263:Deoxyribonucleases, Type III Site-Specific