Heterogeneity in tandem octanucleotides within Haemophilus influenzae lipopolysaccharide biosynthetic gene losA affects serum resistance.
Heterogeneity in tandem octanucleotides within Haemophilus influenzae lipopolysaccharide biosynthetic gene losA affects serum resistance.
复制标题
流感嗜血杆菌脂多糖生物合成基因losA内串联八核苷酸的异质性影响血清抵抗。
DOI：
10.1128/iai.01540-05
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Smith,ArnoldL
中科院分区：
文献类型：
--
作者：
Erwin,AliceL;Bonthuis,PaulJ;Geelhood,JenniferL;Nelson,KevinL;McCrea,KirkW;Gilsdorf,JanetR;Smith,ArnoldL
Haemophilus influenzaeis subject to phase variation mediated by changes in the length of simple sequence repeat regions within several genes, most of which encode either surface proteins or enzymes involved in the synthesis of lipopolysaccharides (LPS). The translational repeat regions that have been described thus far all consist of tandemly repeated tetranucleotides. We describe an octanucleotide repeat region within a putative LPS biosynthetic gene,losA. Approximately 20 percent of nontypeableH. influenzaestrains contain copies oflosAandlosBin a genetic locus flanked byinfAandksgA. Of 30 strains containinglosAat this site, 24 contained 2 tandem copies of the octanucleotide CGAGCATA, allowing full-length translation oflosA(on), and 6 strains contained 3, 4, 6, or 10 tandem copies (losAoff). For a serum-sensitive strain, R3063, withlosAoff (10 repeat units), selection for serum-resistant variants yielded a heterogeneous population in which colonies with increased serum resistance hadlosAon (2, 8, or 11 repeat units), and colonies with unchanged sensitivity to serum had 10 repeats. Inactivation oflosAin strains R3063 and R2846 (strain 12) by insertion of thecatgene decreased the serum resistance of these strains compared tolosA-on variants and altered the electrophoretic mobility of LPS. We conclude that expression oflosA, a gene that contributes to LPS structure and affects serum resistance, is determined by octanucleotide repeat variation.
