Structure of bovine prothrombin fragment 1 refined at 2.25 A resolution.
Structure of bovine prothrombin fragment 1 refined at 2.25 A resolution.
复制标题
以 2.25 A 分辨率精制的牛凝血酶原片段 1 的结构。
DOI：
10.1016/0022-2836(91)90025-2
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发表时间：
1991
影响因子：
5.6
通讯作者：
Park,CH
中科院分区：
文献类型：
--
作者：
Seshadri,TP;Tulinsky,A;Skrzypczak-Jankun,E;Park,CH
牛凝血酶原片段1的结构已在2.25 μ m的分辨率，使用高分辨率的测量与同步加速器光束在CHESS进行了细化。同步加速器数据通过振荡方法（R-merge= 0.08）收集。这些与低阶衍射仪数据相结合，用于细化目的。使用约束最小二乘法和程序PROLSQ将结构精修至0.175的晶体学R值。该结构包含105个水分子，占据比>0·6。片段1的N-末端γ-羧基谷氨酸结构域（Ala 1-Cys 48）的前35个残基（Ala 1-Leu 35）是无序的，就像Mr β 5000的两条糖链一样;后两条联合收割机使40%的结构无序。片段1的kringle的折叠与内环二硫基之间的紧密分子内接触有关。Kringle的保守序列的一半形成围绕这些二硫键基团的内核。序列保守性的其余部分与主链的许多转角有关。尽管核磁共振研究表明纤溶酶原Kringle 4的类似残基具有两个位置，但Kringle的Pro 95残基具有不对称构象，Tyr 74在片段1中有序。表面可及性计算表明，片段1的二硫基中没有一个是溶剂可及的。
The structure of bovine prothrombin fragment 1 has been refined at 2.25 Å resolution using high resolution measurements made with the synchrotron beam at CHESS. The synchrotron data were collected photographically by oscillation methods (R-merge= 0.08). These were combined with lower order diffractometer data for refinement purposes. The structure was refined using restrained least-squares methods with the program PROLSQ to a crystallographicR-value of 0.175. The structure includes 105 water molecules with occupancies of >0·6. The first 35 residues (Ala1-Leu35) of the N-terminal γ-carboxy glutamic acid-domain (Ala1-Cys48) of fragment 1 are disordered as are two carbohydrate chains ofMr≈ 5000; the latter two combine to render 40% of the structure disordered. The folding of the kringle of fragment 1 is related to the close intramolecular contact between the inner loop disulfide groups. Half of the conserved sequence of the kringle forms an inner core surrounding these disulfide groups. The remainder of the sequence conservation is associated with the many turns of the main chain. The Pro95 residue of the kringle has acisconformation and Tyr74 is ordered in fragment 1, although nuclear magnetic resonance studies indicate that the comparable residue of plasminogen kringle 4 has two positions. Surface accessibility calculations indicate that none of the disulfide groups of fragment 1 is accessible to solvent.