Y1转座酶关联转座子在大肠杆菌和沙门氏菌基因组中的分布和结构特征OACSTPCD

Y1 is a transposase that contains one tyrosine in its catalytic center,and it is capable of cleaving and ligating single-stranded DNA.Y1-associated transposons(Y1ATs)are widely distributed among prokaryotes.To explore the systematic evolutionary characteristics of Y1ATs in the genomes of two bacterial strains,Escherichia coli(E.coli)and Salmonella enterica(S.ente),which is done by mining and analyzing Y1ATs using the Hmmsearch program.The results indicate that Y1ATs are widely distributed in 96.84%of the E.coli genome and 80.4%of the S.ente genome.Based on sequence alignment and protein structure domain prediction,Y1ATs are classified into 10 classes,all belonging to the IS200/IS605 superfamily,with 11 645 belonging to the IS200 family and 4,811 belonging to the IS605 family.The IS200 family is widely distributed in the S.ente genome(72.24%),while the IS605 family is highly distributed in the E.coli genome(89.38%).The number of IS200 copies and intact copies are significantly higher than that of IS605.The IS200 family has only one Y1 transposase coding region,while the IS605 family has two open reading frames,encoding Y1 transposase and TnpB protein,respectively.The amino acid sequence of Y1 in the IS200 family is highly conserved(95.3%).In contrast,Y1 and TnpB in the IS605 family exhibit genetic diversity,which can provide significant insights into the genetic evolutionary pattern of transposons among prokaryotes.The IS200 family containing a highly conserves Y1 transposase with a high proportion of intact copies suggests that this type of transposon may have transpositional activity.Exploring its activity could be beneficial in developing novel and efficient transposon-mediated gene editing tools.