title: The AplI restriction-modification system in an edible cyanobacterium, Arthrospira (Spirulina) platensis NIES-39, recognizes the nucleotide sequence 5'-CTGCAG-3'.
abstract: The degradation of foreign DNAs by restriction enzymes in an edible cyanobacterium, Arthrospira platensis, is a potential barrier for gene-transfer experiments in this economically valuable organism. We overproduced in Escherichia coli the proteins involved in a putative restriction-modification system of A. platensis NIES-39. The protein produced from the putative type II restriction enzyme gene NIES39_K04640 exhibited an endonuclease activity that cleaved DNA within the sequence 5'-CTGCAG-3' between the A at the fifth position and the G at the sixth position. We designated this enzyme AplI. The protein from the adjacent gene NIES39_K04650, which encodes a putative DNA (cytosine-5-)-methyltransferase, rendered DNA molecules resistant to AplI by modifying the C at the fourth position (but not the C at the first position) in the recognition sequence. This modification enzyme, M.AplI, should be useful for converting DNA molecules into AplI-resistant forms for use in gene-transfer experiments. A summary of restriction enzymes in various Arthrospira strains is also presented in this paper.
authors.affiliation: Graduate School of Biostudies, Kyoto University, Kyoto, Japan. siraisi@kuchem.kyoto-u.ac.jp
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shiraishi
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Tabuse
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D004262:DNA Restriction Enzymes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005516:Food Microbiology; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D053545:Spirulina / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D004269:DNA, Bacterial; D011994:Recombinant Proteins; D004262:DNA Restriction Enzymes