Biochemical characterization and crystal structure of a GH10 xylanase from termite gut bacteria reveal a novel structural feature and significance of its bacterial Ig-like domain

2013 ◽  
Vol 110 (12) ◽  
pp. 3093-3103 ◽  
Author(s):  
Qian Han ◽  
Ning Liu ◽  
Howard Robinson ◽  
Lin Cao ◽  
Changli Qian ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structural Feature ◽  
Biochemical Characterization ◽  
Gut Bacteria ◽  
Termite Gut ◽  
Gh10 Xylanase

scholarly journals Crystal structure of steroid reductase SRD5A reveals conserved steroid reduction mechanism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yufei Han ◽  
Qian Zhuang ◽  
Bo Sun ◽  
Wenping Lv ◽  
Sheng Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biochemical Characterization ◽  
Substrate Binding ◽  
Binding Pocket ◽  
Substrate Binding Pocket ◽  
Transmembrane Segments ◽  
Therapeutic Molecules ◽  
Binding Cavity ◽  
Immune System Regulation ◽  
Mediated Reduction

AbstractSteroid hormones are essential in stress response, immune system regulation, and reproduction in mammals. Steroids with 3-oxo-Δ4 structure, such as testosterone or progesterone, are catalyzed by steroid 5α-reductases (SRD5As) to generate their corresponding 3-oxo-5α steroids, which are essential for multiple physiological and pathological processes. SRD5A2 is already a target of clinically relevant drugs. However, the detailed mechanism of SRD5A-mediated reduction remains elusive. Here we report the crystal structure of PbSRD5A from Proteobacteria bacterium, a homolog of both SRD5A1 and SRD5A2, in complex with the cofactor NADPH at 2.0 Å resolution. PbSRD5A exists as a monomer comprised of seven transmembrane segments (TMs). The TM1-4 enclose a hydrophobic substrate binding cavity, whereas TM5-7 coordinate cofactor NADPH through extensive hydrogen bonds network. Homology-based structural models of HsSRD5A1 and -2, together with biochemical characterization, define the substrate binding pocket of SRD5As, explain the properties of disease-related mutants and provide an important framework for further understanding of the mechanism of NADPH mediated steroids 3-oxo-Δ4 reduction. Based on these analyses, the design of therapeutic molecules targeting SRD5As with improved specificity and therapeutic efficacy would be possible.

scholarly journals Structural and biochemical characterization of bifunctional XynA

2020 ◽  
Author(s):  
Wei Xie ◽  
Qi Yu ◽  
Yun Liu ◽  
Ruoting Cao ◽  
Ruiqing Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Enzyme Activity ◽  
Catalytic Mechanism ◽  
Biochemical Characterization ◽  
Cellulase Activity ◽  
Cost Savings ◽  
Site Directed Mutagenesis ◽  
Enzyme Activity Assay ◽  
Great Cost ◽  
Terminal Domain

AbstractXylan and cellulose are the two major constituents in numerous types of lignocellulosic biomass, representing a promising resource for biofuels and other biobased industries. The efficient degradation of lignocellulose requires the synergistic actions of cellulase and xylanase. Thus, bifunctional enzyme incorporated xylanase/cellulase activity has attracted considerable attention since it has great cost savings potential. Recently, a novel GH10 family enzyme XynA identified from Bacillus sp. is found to degrade both cellulose and xylan. To understand its molecular catalytic mechanism, here we first solve the crystal structure of XynA at 2.3 Å. XynA is characterized with a classic (α/β)8 TIM-barrel fold (GH10 domain) flanked by the flexible N-terminal domain and C-terminal domain. Circular dichroism, protein thermal shift and enzyme activity assays reveal that conserved residues Glu182 and Glu280 are both important for catalytic activities of XynA, which is verified by the crystal structure of XynA with E182A/E280A double mutant. Molecular docking studies of XynA with xylohexaose and cellohexaose as well as site-directed mutagenesis and enzyme activity assay demonstrat that Gln250 and His252 are indispensible to cellulase and bifunctional activity, separately. These results elucidate the structural and biochemical features of XynA, providing clues for further modification of XynA for industrial application.

Crystal structure and biochemical characterization of the transmembrane PAP2 type phosphatidylglycerol phosphate phosphatase from Bacillus subtilis

2017 ◽  
Vol 74 (12) ◽  
pp. 2319-2332 ◽  
Author(s):  
Meriem El Ghachi ◽  
Nicole Howe ◽  
Rodolphe Auger ◽  
Alexandre Lambion ◽  
Annick Guiseppi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Bacillus Subtilis ◽  
Biochemical Characterization

scholarly journals Sequencing, biochemical characterization, crystal structure and molecular dynamics of cellobiohydrolase Cel7A fromGeotrichum candidum3C

FEBS Journal ◽  
2015 ◽  
Vol 282 (23) ◽  
pp. 4515-4537 ◽  
Author(s):  
Anna S. Borisova ◽  
Elena V. Eneyskaya ◽  
Kirill S. Bobrov ◽  
Suvamay Jana ◽  
Anton Logachev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Biochemical Characterization
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