CRYSTALLOGRAPHIC STUDIES OF FRAGMENTS FROM REGULATED MYOSIN

调节肌球蛋白片段的晶体学研究

• 批准号: 7357705
• 负责人: CAROLYN COHEN
• 金额: $ 3.75万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7357705
• 关键词: CRYSTALLOGRAPHIC; STUDIES; FRAGMENTS; REGULATED; MYOSIN

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have collected crystal data from both the head and tail regions of scallop myosin. Following our recent study on the high-resolution crystal structure of the actin-detached, internally-uncoupled state of the scallop myosin head (S1) (Himmel, et al., in preparation; reported in our CHESS Progress Report of 2001), we have now obtained a 2.6A resolution structure of S1 in the pre-power stroke or primed conformation (Gourinath, et al., in preparation). Comparison of these two structures, which differ greatly in subdomain interactions, will provide key information on the flexibility of linkages in different states of the contractile cycle. Until now, there has not been a detailed structure reported for any part of the tail of myosin. Using data collected to 2.6A resolution at CHESS, we are determining the structure of a 50-residue-long segment of the scallop myosin tail, located adjacent to the myosin head. This region of the tail is critical for the regulatory properties of the myosin molecule (Li et al., in preparation). Based on data collected at CHESS during the past few years, we have also published reports on crystal structures of key fragments of tropomyosin and fibrinogen. Following our work on an N-terminal fragment of tropomyosin (Brown et al., 2001), we have now established the structure of a 31-residue C-terminal segment of striated-muscle tropomyosin, which shows an unusual splayed conformation. These results reveal a specific recognition site for troponin T and clarify the physical basis for the unique regulatory mechanism of striated muscles (Li et al., PNAS, in press). In our efforts to understand the molecular basis of blood clotting, we have also pursued crystal structures of fibrinogen. We previously reported the 4A structure of the 285 kDa backbone of bovine fibrinogen (Brown et al., 2000), and have now achieved a 1.4A resolution structure of the central domain of the molecule (Madrazo et al., 2001). This structure has a remarkable dimeric interface, which could not previously be visualized. Taken together, these results have improved our understanding of the assembly of the molecule into the fibrinogen clot.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。我们已经从扇贝肌球蛋白的头部和尾部区域收集了晶体数据。在我们最近关于肌动蛋白触觉，内部脉冲肌球蛋白头（S1）的高分辨率晶体结构的研究之后（Himmel等人在2001年的国际象棋进度报告中进行了报道），我们现在已经获得了PRES PORESTOR PROTER STROKE STROKE STROKE STROKE或PRINED PRINED PRINEDERAKE的2.6a分辨率结构。这两种结构在亚域相互作用中的比较将提供有关收缩周期不同状态链接的灵活性的关键信息。到目前为止，还没有针对肌球蛋白尾部的任何部分报告详细的结构。使用在国际象棋处收集到2.6A分辨率的数据，我们确定位于肌球蛋白头附近的扇贝肌球蛋白尾部的50分长段的结构。尾部的该区域对于肌球蛋白分子的调节特性至关重要（在制备中，Li等人）。基于过去几年在国际象棋收集的数据，我们还发布了有关肌动蛋白和纤维蛋白原关键碎片晶体结构的报告。在我们对肌动蛋白的N末端片段的工作（Brown等，2001），我们现在已经建立了横纹肌肉肌动蛋白的31个残留C末端段的结构，这表明了异常的构型。这些结果揭示了肌钙蛋白T的特定识别位点，并阐明了横纹肌肉独特的调节机制的物理基础（Li等，PNAS，印刷中）。为了理解血液凝结的分子基础，我们还追求了纤维蛋白原的晶体结构。我们以前报道了牛纤维蛋白原的285 kDa主链的4A结构（Brown等，2000），现在已经达到了该分子中心结构域的1.4A分辨率结构（Madrazo等，2001）。该结构具有显着的二聚体界面，以前无法可视化。综上所述，这些结果改善了我们对分子组装到纤维蛋白原凝块中的理解。