华南农业大学学报
華南農業大學學報
화남농업대학학보
JOURNAL OF SOUTH CHINA AGRICULTURAL UNIVERSITY
2015年
2期
49-54
,共6页
董会娟%余永红%王海洪%马金成
董會娟%餘永紅%王海洪%馬金成
동회연%여영홍%왕해홍%마금성
野油菜黄单胞菌%3-酮脂酰ACP合成酶%遗传互补
野油菜黃單胞菌%3-酮脂酰ACP閤成酶%遺傳互補
야유채황단포균%3-동지선ACP합성매%유전호보
Xanthomonas campestris%3-ketoacyl-ACP synthase%genetic complementary
目的研究野油菜黄单胞菌Xanthomonas campestris 8004基因组中3个标注为3-酮脂酰ACP合成酶的基因XcfabF1、XcfabF2和XcfabB在脂肪酸合成过程中的功能．方法将这3个基因分别克隆到表达载体pBAD24M，然后转化大肠埃希菌Escherichia coli的fabB和fabF温敏型突变株CY242和CY244，同时利用体外无细胞抽提物酶学分析FabF1、FabF2和FabB蛋白活性．结果和结论 XcfabF1和XcfabB基因分别能遗传互补大肠埃希菌fabF和fabB突变，而XcfabF2基因则不能互补大肠埃希菌fabF或fabB突变．体外无细胞抽提物酶学分析表明FabF1和FabB都能完成辛脂酰-ACP的延伸，但FabF2则不能完成该酶促反应．XcfabB基因编码3-酮脂酰ACP合成酶I，Xc-fabF1基因编码3-酮脂酰ACP合成酶II，而fabF2基因不参与中长链脂肪酸的合成．
目的研究野油菜黃單胞菌Xanthomonas campestris 8004基因組中3箇標註為3-酮脂酰ACP閤成酶的基因XcfabF1、XcfabF2和XcfabB在脂肪痠閤成過程中的功能．方法將這3箇基因分彆剋隆到錶達載體pBAD24M，然後轉化大腸埃希菌Escherichia coli的fabB和fabF溫敏型突變株CY242和CY244，同時利用體外無細胞抽提物酶學分析FabF1、FabF2和FabB蛋白活性．結果和結論 XcfabF1和XcfabB基因分彆能遺傳互補大腸埃希菌fabF和fabB突變，而XcfabF2基因則不能互補大腸埃希菌fabF或fabB突變．體外無細胞抽提物酶學分析錶明FabF1和FabB都能完成辛脂酰-ACP的延伸，但FabF2則不能完成該酶促反應．XcfabB基因編碼3-酮脂酰ACP閤成酶I，Xc-fabF1基因編碼3-酮脂酰ACP閤成酶II，而fabF2基因不參與中長鏈脂肪痠的閤成．
목적연구야유채황단포균Xanthomonas campestris 8004기인조중3개표주위3-동지선ACP합성매적기인XcfabF1、XcfabF2화XcfabB재지방산합성과정중적공능．방법장저3개기인분별극륭도표체재체pBAD24M，연후전화대장애희균Escherichia coli적fabB화fabF온민형돌변주CY242화CY244，동시이용체외무세포추제물매학분석FabF1、FabF2화FabB단백활성．결과화결론 XcfabF1화XcfabB기인분별능유전호보대장애희균fabF화fabB돌변，이XcfabF2기인칙불능호보대장애희균fabF혹fabB돌변．체외무세포추제물매학분석표명FabF1화FabB도능완성신지선-ACP적연신，단FabF2칙불능완성해매촉반응．XcfabB기인편마3-동지선ACP합성매I，Xc-fabF1기인편마3-동지선ACP합성매II，이fabF2기인불삼여중장련지방산적합성．
Objective]The functions of the three genes XcfabF1, XcfabF2 and XcfabB, which were anno-tated as encodes putative 3-ketoacyl-ACP synthase in fatty acid synthesis in Xanthomonas campestris 8004 genome, were studied.[Method] Three genes coloned into expression plasmid pBAD 24M separately were transformed into the fabB and fabF temperature sensitive mutant CY 242 and CY244 of Escherichia coli.The activity of XcFabF1, XcFabF2 and XcFabB in vitro was assayed by cell-free extracts.[Result and conclusion]The genetic complementary revealed that XcfabB and XcfabF1 genes could restore the growth of mutant CY242 and CY244 respectively, but XcfabF2 could not restore the growth of mutant CY242 or CY244 .The cell-free extracts of XcFabF1 and XcFabB could elongate octanoyl-ACP to longer acyl-ACP, while XcFabF2 could not catalyse the elongation in vitro assay.The above results demonstrate that XcfabB and XcfabF1 encode 3-ketoacyl-ACP sysnthase I and 3-ketoacyl-ACP sysnthase II respective-ly, but XcfabF2 is not involved in long chain fatty acid synthesis in X.campestris.
