TY - JOUR
T1 - Multiplication of a restriction-modification gene complex
AU - Sadykov, Marat
AU - Asami, Yasuo
AU - Niki, Hironori
AU - Handa, Naofumi
AU - Itaya, Mitsuhiro
AU - Tanokura, Masaru
AU - Kobayashi, Ichizo
PY - 2003/4
Y1 - 2003/4
N2 - Previous works have suggested that some gene complexes encoding a restriction (R) enzyme and a cognate modification (M) enzyme may behave as selfish mobile genetic elements. RM gene complexes, which destroy 'non-self' elements marked by the absence of proper methylation, are often associated with mobile genetic elements and are involved in various genome rearrangements. Here, we found amplification of a restriction-modification gene complex. BamHI gene complex inserted into the Bacillus chromosome showed resistance to replacement by a homologous stretch of DNA. Some cells became transformed with the donor without losing BamHI. In most of these transformants, multiple copies of BamHI and the donor allele were arranged as tandem repeats. When a clone carrying one copy of each allele was propagated, extensive amplification of BamHI and the donor unit was observed in a manner dependent on restriction enzyme gene. This suggests that restriction cutting of the genome participates in the amplification. Visualization by fluorescent in situ hybridization revealed that the amplification occurred in single cells in a burst-like fashion that is reminiscent of induction of provirus replication. The multiplication ability in a bacterium with natural capacity for DNA release, uptake and transformation will be discussed in relation to spreading of RM gene complexes.
AB - Previous works have suggested that some gene complexes encoding a restriction (R) enzyme and a cognate modification (M) enzyme may behave as selfish mobile genetic elements. RM gene complexes, which destroy 'non-self' elements marked by the absence of proper methylation, are often associated with mobile genetic elements and are involved in various genome rearrangements. Here, we found amplification of a restriction-modification gene complex. BamHI gene complex inserted into the Bacillus chromosome showed resistance to replacement by a homologous stretch of DNA. Some cells became transformed with the donor without losing BamHI. In most of these transformants, multiple copies of BamHI and the donor allele were arranged as tandem repeats. When a clone carrying one copy of each allele was propagated, extensive amplification of BamHI and the donor unit was observed in a manner dependent on restriction enzyme gene. This suggests that restriction cutting of the genome participates in the amplification. Visualization by fluorescent in situ hybridization revealed that the amplification occurred in single cells in a burst-like fashion that is reminiscent of induction of provirus replication. The multiplication ability in a bacterium with natural capacity for DNA release, uptake and transformation will be discussed in relation to spreading of RM gene complexes.
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U2 - 10.1046/j.1365-2958.2003.03464.x
DO - 10.1046/j.1365-2958.2003.03464.x
M3 - Article
C2 - 12675801
AN - SCOPUS:0037673304
SN - 0950-382X
VL - 48
SP - 417
EP - 427
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 2
ER -