(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Bilateria: NE > Protostomia: NE > Ecdysozoa: NE > Panarthropoda: NE > Arthropoda: NE > Chelicerata: NE > Arachnida: NE > Acari: NE > Parasitiformes: NE > Ixodida: NE > Ixodoidea: NE > Ixodidae: NE > Rhipicephalinae: NE > Rhipicephalus [genus]: NE > Boophilus: NE > Rhipicephalus microplus: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MAVKAAVLIGVILAFNLTATAEDMHVERETTEGRVRGKVVHVLDNEPVEE YVGIPYAEPPLDKLRFRPPQPKKRWQDTLDATSTRTACPQIEMQLVIMNN VTYTEDCLHLNIWVPEKAMNPGAKQPVLVWIHGGGFTFGSANQWEYNGAV LAATTDVVVVAMNYRLSILGFMSANSPEAPGNVGMLDQVMVLKWIQRNIE HFGGDPDRVTLFGESAGAMSAHAHVLSPMSEGLFKRAVLMSGTMYNIDLW DMVHESMVKGNKVANIVGCSKGGSIDLSSNAEEIVDCFRKKSADELVKAA AESVAPKKIPFAPIYHDAFLPKMPLVAMNRGFFASVDIVAGVTSDEGALA LVFPPKLELLPDDLDGSNPEKLKDSLRTALSSWVKEDIPDIEDKYADDAP QGDGNALRRQYLDYLSDRLFNCPLQFFAEKHSERGNKVFAYVFGHKYDAF NLPAWMGVPHATDLQFAFGIPYAAERDSLNGRMSEAYMRMLGSFSENGRP ELPSKQKWPRYTKRSPTVIHMNSDHFNETKGFRAEQCERWKSLF
References
Title: Gene structure and expression of a pyrethroid-metabolizing esterase, CzEst9, from a pyrethroid resistant Mexican population of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) Guerrero FD, Nene VM Ref: Journal of Medical Entomology, 45:677, 2008 : PubMed
A population of Rhipicephalus (Boophilus) microplus (Canestrini) (Acari: Ixodidae), designated Coatzacoalcos, sampled from a ranch near Veracruz, Mexico, was found to possess a high level of resistance to pyrethroid-based acaricides. Bioassay and biochemical and molecular analysis had previously shown that resistance in this population could primarily be attributed to expression of a highly active metabolic esterase designated CzEST9. We cloned and sequenced the entire CzEST9 coding region, including introns and > 1.0 kb upstream from the transcription start site, and we compared the upstream region sequence between individual resistant and susceptible ticks from several populations with different pyrethroid resistance characteristics. In the 1.0-kb upstream region sequence, four variant nucleotides were found, and a TGA trinucleotide occurred as either four, five, or nine tandem repeats. However, none of these promoter region sequence differences could be clearly associated with a pyrethroid-resistant phenotype; thus, we concluded that differences in gene promoter sequence were not responsible for the pyrethroid resistance mechanism in the Cz strain. CzEST9 was expressed in recombinant Escherichia coli and Pichia pastoris systems and esterase activity was obtained in recombinant CzEST9 from the P. pastoris system.
Two esterase cDNA sequences were obtained from susceptible and organophosphorus resistant strains of Boophilus microplus. Both sequences have a high degree of homology to carboxylesterase B. One gene has identical sequences in both strains and the other showed two point mutations. One mutation produces an amino acid substitution when the amino acid sequence is deduced, this mutation was detected in six different populations susceptible and resistant to insecticides, but a pyrethroid resistant strain was the only one that showed only the mutant allele. Identification of this mutation and the strong signal detected in southern blot with this strain, suggest that esterases are contributing to detoxification of pyrethroid compounds, as a resistant mechanism in Mexican strains of the southern cattle tick.
