Zhao Liu

Publications (3)15.04 Total impact

• Article: Crystallization and preliminary X-ray studies of ferric uptake regulator from Magnetospirillum gryphiswaldense.

  Zhao Liu, Zhongzhou Chen, Wei Wu
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  ABSTRACT: Magnetosomes in magnetotactic bacteria have been widely used in studies of magnetic domains and in commercial applications. The iron content of magnetotactic bacteria is ∼100 times higher than that of Escherichia coli. Magnetospirillum gryphiswaldense MSR-1 can still take up iron even at high intracellular concentrations. Ferric uptake regulator (Fur) is a global iron-responsive regulator that affects magnetosome formation, iron transport and oxygen metabolism. However, the mechanism of iron uptake and homeostasis by M. gryphiswaldense MSR-1 Fur is not clear. Here, the expression, purification and crystallization of apo and SeMet Fur from M. gryphiswaldense MSR-1 are reported. The crystals belonged to space group C2. Matthews coefficient analysis and size-exclusion chromatography showed that the asymmetric unit probably contains one dimer of Fur. Diffraction data were optimized to 1.58 Å resolution for apo Fur and to 1.9 Å resolution for SeMet Fur.
  Acta Crystallographica Section F Structural Biology and Crystallization Communications 08/2012; 68(Pt 8):902-5. · 0.51 Impact Factor
• Article: Complex structures of the abscisic acid receptor PYL3/RCAR13 reveal a unique regulatory mechanism.

  Xingliang Zhang, Qi Zhang, Qi Xin, Lin Yu, Zheng Wang, Wei Wu, Lun Jiang, Guoqiang Wang, Wenli Tian, Zengqin Deng, Yang Wang, Zhao Liu, Jiafu Long, Zhizhong Gong, Zhongzhou Chen
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  ABSTRACT: Abscisic acid (ABA) controls many physiological processes and mediates adaptive responses to abiotic stresses. The ABA signaling mechanisms for abscisic acid receptors PYR/PYL/RCAR (PYLs) were reported. However, it remains unclear whether the molecular mechanisms are suitable for other PYLs. Here, complex structures of PYL3 with (+)-ABA, pyrabactin and HAB1 are reported. An unexpected trans-homodimer intermediate observed in the crystal is confirmed in solution. ABA-bound PYL3 greatly promotes the generation of monomeric PYL3, which can excessively increase the efficiency of inhibiting PP2Cs. Structure-guided biochemical experiments show that Ser195 accounts for the key intermediate. Interestingly, pyrabactin binds to PYL3 in a distinct nonproductive mode with gate closure, which sheds light on the design of agonists and antagonists for abscisic acid receptors. According to different conformations of ligand-bound PYLs, the PYLs family can be divided into three subclasses, among which the trans-dimeric subclass, represented by PYL3, reveals a distinct regulatory mechanism.
  Structure 05/2012; 20(5):780-90. · 6.35 Impact Factor
• Source

  Available from: Zhongzhou Chen

  Article: Structural insights into a novel histone demethylase PHF8.

  Lin Yu, Yang Wang, Shuo Huang, Jianjun Wang, Zengqin Deng, Qi Zhang, Wei Wu, Xingliang Zhang, Zhao Liu, Weimin Gong, Zhongzhou Chen
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  ABSTRACT: Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain (PHD) finger protein 8 (PHF8) are associated with X-linked mental retardation and facial anomalies, such as a long face, broad nasal tip, cleft lip/cleft palate and large hands, yet its molecular function and structural basis remain unclear. Here, we report the crystal structures of the catalytic core of PHF8 with or without alpha-ketoglutarate (alpha-KG) at high resolution. Biochemical and structural studies reveal that PHF8 is a novel histone demethylase specific for di- and mono-methylated histone H3 lysine 9 (H3K9me2/1), but not for H3K9me3. Our analyses also reveal how human PHF8 discriminates between methylation states and achieves sequence specificity for methylated H3K9. The in vitro demethylation assay also showed that the F279S mutant observed in clinical patients possesses no demethylation activity, suggesting that loss of enzymatic activity is crucial for pathogenesis of PHF8 patients. Taken together, these results will shed light on the molecular mechanism underlying PHF8-associated developmental and neurological diseases.
  Cell Research 02/2010; 20(2):166-73. · 8.19 Impact Factor