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Binding asymmetry and conformational studies of the AtGSDA dimer.

ABSTRACT: Guanosine deaminase (GSDA) is an important deaminase that converts guanosine to xanthosine, a key intermediate in nitrogen recycling in plants. We previously solved complex structures of Arabidopsis thaliana GSDA bound by various ligands and examined its catalytic mechanism. Here, we report cocrystal structures of AtGSDA bound by inactive guanosine derivatives, which bind relatively weakly to the enzyme and mostly have poor binding geometries. The two protomers display unequal binding performances, and molecular dynamics simulation identified diverse conformations during the enzyme-ligand interactions. Moreover, intersubunit, tripartite salt bridges show conformational differences between the two protomers, possibly acting as "gating" systems for substrate binding and product release. Our structural and biochemical studies provide a comprehensive understanding of the enzymatic behavior of this intriguing enzyme.

SUBMITTER: Jia Q

PROVIDER: S-EPMC10663702 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature

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Binding asymmetry and conformational studies of the AtGSDA dimer.

Jia Qian Q Zeng Hui H Li Mingwei M Tang Jing J Xiao Nan N Gao Shangfang S Li Huanxi H Zhang Jinbing J Zhang Zhiyong Z Xie Wei W

Computational and structural biotechnology journal 20231104

Guanosine deaminase (GSDA) is an important deaminase that converts guanosine to xanthosine, a key intermediate in nitrogen recycling in plants. We previously solved complex structures of <i>Arabidopsis thaliana</i> GSDA bound by various ligands and examined its catalytic mechanism. Here, we report cocrystal structures of AtGSDA bound by inactive guanosine derivatives, which bind relatively weakly to the enzyme and mostly have poor binding geometries. The two protomers display unequal binding per ...[more]

PMID: 38022696

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Dataset Information

Binding asymmetry and conformational studies of the AtGSDA dimer.

Publications

Binding asymmetry and conformational studies of the AtGSDA dimer.

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