DATA COLLECTION ON CRYSTALS OF REGULATORY SUBUNIT OF PKA

在生物体的分子结构中，腺苷3 '-5' 一磷酸（环AMP或cAMP）一直是普遍的第二个 使者 在真核细胞中，cAMP的主要受体是 cAMP依赖性蛋白激酶的调节亚基。 晶体 Ia型调节亚基1-91缺失突变体的结构 利用SSRL的7-1束线数据，将其精度提高到2.8E。 两个串联的cAMP结合结构域中的每一个都提供了广泛的 氢键的网络，它掩埋了环状磷酸盐和 两条链之间的核糖由一个短的？螺旋。 每一个腺嘌呤碱基都与一个位于外侧的芳香环相重叠 桶_桶 这种结构提供了一个分子基础， 了解cAMP如何与其受体蛋白协同结合， 从而介导激酶的活化。 自从确定 缺失突变体结构，野生型Ia调节的晶体 二聚体已经获得。 一个低分辨率的4.5 E数据集， 在实验室源中收集晶体。 我们还没有 我们从同步加速器获得更好数据的尝试取得了成功 源头

In the molecular scheme of living organisms, adenosine 3'-5' monophosphate (cyclic AMP or cAMP) has been a universal second messenger. In eukaryotic cells, the primary receptor for cAMP are regulatory subunits of cAMP-dependent protein kinase. The crystal structure of a 1-91 deletion mutant of the type Ia regulatory subunit was refined to 2.8 E resolution using data from 7-1 beam line of SSRL. Each of the two tandem cAMP binding domains provides an extensive network of hydrogen bonds that buries the cyclic phosphate and the ribose between the two _ -strands that are linked by a short ?-helix. Each adenine base stacks against an aromatic ring that lies outside the _-barrel. This structure provides a molecular basis of understanding how cAMP binds cooperatively to its receptor protein, thus mediating activation of the kinase. Since the determination of the deletion mutant structure, crystals of the wild-type Ia regulatory dimer have been obtained. A low resolution 4.5 E data set from these crystals was collected in the laboratory source. We have yet to succeed in our attempts to get better data from the synchrotron source.