Gene Enzyme and Physiological Characterization of shrunken-2Isoalleles

shrunken-2 等位基因的基因酶和生理特征

• 批准号: 9316887
• 负责人: L. Curtis Hannah
• 金额: $ 32.18万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-01 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316887&HistoricalAwards=false
• 关键词: Gene; Enzyme; Physiological; Characterization; shrunken

9316887 Hannah The allosteric properties of ADP-glucose pyrophosphorylase are critical in controlling the amount of glucose polymers in organisms ranging from E. coli to potato. The maize transposable element, dissociation Ds, was placed within the coding region of the site of a gene encoding the maize endosperm enzyme. Ds excisions are imprecise, thus revertants represent a series of closely-related mutations arising from one position in the gene. This form of in- vivo, site-specific mutagenesis was used to create wild type variants that differ in DNA sequence, enzyme levels, allosteric properties and seed weight. Since starch comprises 70% of seed weight, starch content likely has been altered. This research will further characterize revertants at DNA, enzyme and physiological levels. Additional excision events will identify changes at this site not only restoring gene function, but those not restoring gene function. Integration of studies at the gene, enzyme and physiological levels of the isogenic maize lines will help define the structure/function relationships of a important region of a critical enzyme and how these changes affect starch content. Secondly, these studies are providing new insight into the mechanism of Ds transposition. Unexpectedly some revertants do not easily fit current models of transposition. Additional excision events should lead to modification of existing models or to development of new ones. In summary, a series of integrated experiments are proposed to more clearly understand how this region of the enzyme affects its allosteric properties and, in turn, how changes affect starch biosynthesis. Coupled with this will be a better understanding of how Ds acts as a mutagen. ***

9316887 Hannah ADP-葡萄糖焦磷酸化酶的变构特性对于控制从大肠杆菌到大肠杆菌的生物体中葡萄糖聚合物的量是至关重要的。从大肠杆菌到马铃薯。 将玉米转座因子，解离Ds，置于编码玉米胚乳酶的基因的位点的编码区内。 Ds切除是不精确的，因此回复突变体代表了基因中一个位置产生的一系列密切相关的突变。 这种形式的体内位点特异性诱变用于产生在DNA序列、酶水平、变构特性和种子重量方面不同的野生型变体。 由于淀粉占种子重量的70%，淀粉含量可能已经改变。 这项研究将进一步在DNA，酶和生理水平上表征回复突变体。 额外的切除事件将鉴定该位点的变化，不仅恢复基因功能，而且不恢复基因功能。 整合等基因玉米系的基因、酶和生理水平的研究将有助于确定关键酶重要区域的结构/功能关系以及这些变化如何影响淀粉含量。 其次，这些研究为Ds转座机制提供了新的见解。 出乎意料的是，一些回复突变体不容易符合目前的转座模型。 更多的切割事件应导致修改现有的模式或开发新的模式。 总之，提出了一系列综合实验，以更清楚地了解该酶的这一区域如何影响其变构特性，进而了解这些变化如何影响淀粉生物合成。 再加上这将是一个更好地了解如何Ds作为一个诱变剂。 ***