rokaryoticgeneregulation：原核基因表達(dá)調(diào)控-wenkub
2023-01-27 08:18:48 本頁(yè)面
【正文】 ply the operon concept to gene expression as it relates to geic engineering (specifically, our cloning and expression of the “tomato” gene). Copyright 169。 2022 Pearson Education, Inc. publishing as Benjamin Cummings Repressible and Inducible Operons: Two Types of Negative Gene Regulation ? A repressible operon is one that is usually on。 2022 Pearson Education, Inc. publishing as Benjamin Cummings ? Inducible enzymes usually function in catabolic pathways ? Repressible enzymes usually function in anabolic pathways ? Regulation of the trp and lac operons involves negative control of genes because operons are switched off by the active form of the repressor Copyright 169。 Positive Regulation a) In the presence of arabinose: ?CAPcAMP plex and araCarabinose plex bind to initiator region ?this allows RNA polymerase to bind to the promoter ?transcription begins b) In the absence of arabinose: ?araC protein assumes a different conformation ?acts as a repressor ?binds to araI and a second operator region araO ?forms a loop ?this loop prevents transcription Copyright 169。 Polycistronic mRNA transcription translation translation translation translation 。 2022 Pearson Education, Inc. publishing as Benjamin Cummings araC regulatory gene repressor Inducer (arabinose) Gene D Arabinose operon with inframe foreign DNA inserted: Tomato gene
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1