Mechanism of Bacterial SMC Complex MukBEF

细菌SMC复合物MukBEF的作用机制

基本信息

批准号：
6931544
负责人：
VALENTIN V RYBENKOV
金额：
$ 18.19万
依托单位：
UNIVERSITY OF OKLAHOMA
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-08-01 至 2006-07-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Chromatin structure undergoes marked, tightly controlled changes during the cell cycle. Maintaining proper chromatin structure is essential for faithful execution of such fundamental events as chromosome replication, recombination, gene expression or cell division. Errors in either of the processes often result in genomic instability and chromosomal alterations potentially leading to carcinogenesis or developmental defects. However molecular mechanisms underlying chromatin dynamics remain largely unknown. The SMC protein family is an emerging group of cellular ATPases responsible for large-scale chromatin reorganizations in organisms ranging from bacteria to humans. These proteins have been implicated in such diverse range of cellular functions as chromosome cohesion and condensation, DNA repair and dosage compensation. It was found recently that the mechanism of 13S condensin, a Xenopus SMC complex responsible for the chromosome condensation during cell division, involves direct ATP-dependent deformation of the large-scale DNA structure. This is an entirely novel kind of enzymatic activity. This project focuses on further mechanistic characterization of the SMC proteins using MukBEF, a bacterial analog of 13S condensin, as a model protein. The specific aims of this project are: (1) characterize biochemical activities of MukBEF; (2) investigate cell cycle regulation of MukBEF; (3) investigate the architecture of MukBEF-DNA complex using electron microscopy; (4) investigate DNA deformation by MukBEF using single DNA manipulation technique. These studies are expected to yield a comprehensive scheme of the MukBEF-catalyzed reaction. These data will contribute to our understanding of the intracellular functions of MukBEF and will illuminate the role of SMC proteins in large scale chromatin dynamics.

描述（由申请人提供）：染色质结构经历标记，在细胞周期中严格控制的变化。保持适当的染色质结构对于忠实执行此类基本事件至关重要染色体复制，重组，基因表达或细胞分裂。错误在任何一个过程中，通常都会导致基因组不稳定性和染色体改变可能导致癌变或发育缺陷。但是，染色质动力学基础的分子机制在很大程度上仍然存在未知。 SMC蛋白质家族是一组新兴的细胞ATPases 负责大规模染色质重新组织的生物中对人类的细菌。这些蛋白质与如此多样化的范围有关细胞的功能充当染色体的凝聚力和凝结，DNA修复和剂量补偿。最近发现，13S冷凝蛋白的机制， Xenopus SMC复合物负责细胞期间染色体冷凝除法，涉及大规模DNA的直接依赖ATP的变形结构。这是一种完全新颖的酶活性。这个项目专注于使用SMC蛋白的进一步机械表征 mukbef，一种13S凝蛋白的细菌类似物，作为模型蛋白。具体该项目的目的是：（1）表征Mukbef的生化活动；（2）研究MUKBEF的细胞周期调节；（3）调查使用电子显微镜的mukbef-DNA复合物的结构；（4）调查 MUKBEF使用单DNA操纵技术对DNA变形。这些预计研究将产生MUKBEF催化的综合方案反应。这些数据将有助于我们对细胞内的理解 MukBef的功能，并将大规模阐明SMC蛋白的作用染色质动力学。