Mechanism of Bacterial SMC Complex MukBEF

细菌SMC复合物MukBEF的作用机制

• 批准号: 6361773
• 负责人: VALENTIN V RYBENKOV
• 金额: $ 15.95万
• 依托单位: UNIVERSITY OF OKLAHOMA
• 依托单位国家: 美国
• 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
• 来源: https://reporter.nih.gov/project-details/6361773
• 关键词: DNA topoisomerases; adenosinetriphosphatase; bacterial genetics; bacterial proteins; cell cycle; chemical kinetics; chromatin; compression; computer simulation; conformation; electron microscopy; enzyme substrate complex; genetic regulation; genetic regulatory element; hydrolysis; immunomagnetic separation; intermolecular interaction; model design /development; nucleic acid metabolism; nucleic acid structure; nucleotide analog; operon; physical model; protein structure function; southern blotting; structural biology

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）：染色质结构经过标记， 严格控制细胞周期中的变化。维持适当的染色质 结构对于忠实执行诸如此类的基本事件至关重要 染色体复制、重组、基因表达或细胞分裂。错误 这两个过程中的任何一个通常都会导致基因组不稳定和染色体 可能导致致癌或发育缺陷的改变。 然而，染色质动力学背后的分子机制在很大程度上仍然存在 未知。 SMC 蛋白家族是一组新兴的细胞 ATP 酶 负责生物体中的大规模染色质重组，包括 细菌对人类。这些蛋白质涉及如此广泛的范围 染色体凝聚和凝结、DNA 修复等细胞功能 剂量补偿。最近发现13S凝缩蛋白的作用机制， 非洲爪蟾 SMC 复合体负责细胞过程中染色体的浓缩 分裂，涉及大规模 DNA 的直接 ATP 依赖性变形 结构。这是一种全新的酶活性。这个项目 重点关注 SMC 蛋白的进一步机制表征 MukBEF 是 13S 凝缩蛋白的细菌类似物，作为模型蛋白。具体的 该项目的目标是：（1）表征 MukBEF 的生化活动； (2)研究MukBEF的细胞周期调控； (3)调查 使用电子显微镜观察 Mu​​kBEF-DNA 复合物的结构； (4)调查 MukBEF 使用单一 DNA 操作技术进行 DNA 变形。这些 研究预计将产生 MukBEF 催化的综合方案 反应。这些数据将有助于我们了解细胞内 MukBEF 的功能并将阐明 SMC 蛋白在大规模中的作用 染色质动力学。