Active site remodelling accompanies thioester bond formation in the SUMO E1.
Active site remodelling accompanies thioester bond formation in the SUMO E1.
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作者：
E1酶激活泛素（Ub）和泛素样（Ubl）蛋白，通过羧基端腺苷化和硫酯键在E1 Cys结构域中形成保守的催化半胱氨酸，分为两步。这些中间体的结构基础尚不清楚。在这里，我们报道了人类SUMO E1与SUMO腺苷酸和四面体中间类似物复合物的晶体结构，分别为2.45 Å和2.6 Å。这些结构表明，在腺苷化后，与ATP·Mg的侧链接触被释放，以促进硫酯键形成过程中Cys结构域的130度旋转，这伴随着关键结构元件的重塑，包括包含E1催化半胱氨酸的螺旋，交叉和再入环，以及腺苷化所需的两个螺旋的重新折叠。这些变化用硫酯键形成所需的侧链取代了腺苷化所需的侧链。突变和生化分析表明，这些机制在其他e1中是保守的。
E1 enzymes activate ubiquitin (Ub) and ubiquitin-like (Ubl) proteins in two steps by carboxy-terminal adenylation and thioester bond formation to a conserved catalytic cysteine in the E1 Cys domain. The structural basis for these intermediates remains unknown. Here we report crystal structures for human SUMO E1 in complex with SUMO adenylate and tetrahedral intermediate analogs at 2.45 Å and 2.6 Å, respectively. These structures show that side chain contacts to ATP·Mg are released after adenylation to facilitate a 130 degree rotation of the Cys domain during thioester bond formation that is accompanied by remodeling of key structural elements including the helix that contains the E1 catalytic cysteine, the cross-over and re-entry loops, and refolding of two helices that are required for adenylation. These changes displace side chains required for adenylation with side chains required for thioester bond formation. Mutational and biochemical analyses suggest these mechanisms are conserved in other E1s.
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影响因子：
15
作者：
Lu, Xuequan;Olsen, Shaun K.;Capili, Allan D.;Cisar, Justin S.;Lima, Christopher D.;Tan, Derek S.
通讯作者：
Tan, Derek S.
影响因子：
16
作者：
Mossessova, E;Lima, CD
通讯作者：
Lima, CD
DOI：
10.1107/s0907444998003254
发表时间：
1998-09-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Brunger, AT;Adams, PD;Warren, GL
通讯作者：
Warren, GL
影响因子：
64.8
作者：
Lake, MW;Wuebbens, MM;Schindelin, H
通讯作者：
Schindelin, H
影响因子：
11.4
作者：
Lois, LM;Lima, CD
通讯作者：
Lima, CD