Mutations on Aromatic Residues of the Active Site To Alter Selectivity of theSulfolobus solfataricusMaltooligosyltrehalose Synthase

2006 ◽  
Vol 54 (10) ◽  
pp. 3585-3590 ◽  
Author(s):  
Tsuei-Yun Fang ◽  
Wen-Chi Tseng ◽  
Yao-Te Chung ◽  
Ching-Hsing Pan
Keyword(s):  
Active Site ◽  
Aromatic Residues

Flexibility of active-site gorge aromatic residues and non-gorge aromatic residues in acetylcholinesterase

2013 ◽  
Vol 67 (7) ◽  
Author(s):  
Pavan GhattyVenkataKrishna ◽  
Neelima Chavali ◽  
Edward Uberbacher
Keyword(s):  
Active Site ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Aromatic Residues

AbstractThe presence of an unusually large number of aromatic residues in the active site gorge of acetylcholinesterase is a subject of great interest. Flexibility of these residues has been suspected to be a key player in controlling the ligand traversal in the gorge. This raises the question of whether the over-representation of aromatic residues in the gorge implies higher-than-normal flexibility of these residues. The current study suggests that it does not. Large changes in the hydrophobic cross-sectional area due to dihedral oscillations are probably the reason of their presence in the gorge.

Site-directed mutagenesis studies of the aromatic residues at the active site of a lipase from Malassezia globosa

Biochimie ◽  
2014 ◽  
Vol 102 ◽  
pp. 29-36 ◽  
Author(s):  
Chongliang Gao ◽  
Dongming Lan ◽  
Lu Liu ◽  
Houjin Zhang ◽  
Bo Yang ◽  
...  
Keyword(s):  
Active Site ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Aromatic Residues ◽  
Malassezia Globosa

Roles of Active Site Aromatic Residues in Catalysis by Ketosteroid Isomerase fromPseudomonas putidaBiotype B†

Biochemistry ◽  
1999 ◽  
Vol 38 (42) ◽  
pp. 13810-13819 ◽  
Author(s):  
Do-Hyung Kim ◽  
Gyu Hyun Nam ◽  
Do Soo Jang ◽  
Gildon Choi ◽  
Soyoung Joo ◽  
...  
Keyword(s):  
Active Site ◽  
Ketosteroid Isomerase ◽  
Aromatic Residues

scholarly journals Crystal Structure of d-Hydantoinase from Burkholderia pickettii at a Resolution of 2.7 Angstroms: Insights into the Molecular Basis of Enzyme Thermostability

2003 ◽  
Vol 185 (14) ◽  
pp. 4038-4049 ◽  
Author(s):  
Zhen Xu ◽  
Yunqing Liu ◽  
Yunliu Yang ◽  
Weihong Jiang ◽  
Eddy Arnold ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Active Site ◽  
Molecular Basis ◽  
Bacillus Stearothermophilus ◽  
Sequence Similarity ◽  
Amino Acid Residues ◽  
Salt Bridges ◽  
Aromatic Residues ◽  
Catalytic Active Site

ABSTRACT d-Hydantoinase (d-HYD) is an industrial enzyme that is widely used in the production of d-amino acids which are precursors for semisynthesis of antibiotics, peptides, and pesticides. This report describes the crystal structure of d-hydantoinase from Burkholderia pickettii (HYDBp) at a 2.7-Å resolution. The structure of HYDBp consists of a core (α/β)8 triose phosphate isomerase barrel fold and a β-sheet domain, and the catalytic active site consists of two metal ions and six highly conserved amino acid residues. Although HYDBp shares only moderate sequence similarity with d-HYDs from Thermus sp. (HYDTsp) and Bacillus stearothermophilus (HYDBst), whose structures have recently been solved, the overall structure and the structure of the catalytic active site are strikingly similar. Nevertheless, the amino acids that compose the substrate-binding site are less conserved and have different properties, which might dictate the substrate specificity. Structural comparison has revealed insights into the molecular basis of the differential thermostability of d-HYDs. The more thermostable HYDTsp contains more aromatic residues in the interior of the structure than HYDBp and HYDBst. Changes of large aromatic residues in HYDTsp to smaller residues in HYDBp or HYDBst decrease the hydrophobicity and create cavities inside the structure. HYDTsp has more salt bridges and hydrogen-bonding interactions and less oxidation susceptible Met and Cys residues on the protein surface than HYDBp and HYDBst. Besides, HYDTsp also contains more rigid Pro residues. These factors are likely to make major contributions to the varying thermostability of these enzymes. This information could be exploited in helping to engineer more thermostable mesophilic enzymes.

Site-directed mutagenesis of two aromatic residues lining the active site pocket of the yeast Ltp1

2007 ◽  
Vol 1770 (5) ◽  
pp. 753-762 ◽  
Author(s):  
Paolo Paoli ◽  
Alessandra Modesti ◽  
Francesca Magherini ◽  
Tania Gamberi ◽  
Anna Caselli ◽  
...  
Keyword(s):  
Active Site ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Aromatic Residues ◽  
Active Site Pocket

scholarly journals Flexibility of Aromatic Residues in the Active-Site Gorge of Acetylcholinesterase: X-ray versus Molecular Dynamics

2008 ◽  
Vol 95 (5) ◽  
pp. 2500-2511 ◽  
Author(s):  
Yechun Xu ◽  
Jacques-Philippe Colletier ◽  
Martin Weik ◽  
Hualiang Jiang ◽  
John Moult ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Active Site ◽  
Aromatic Residues ◽  
X Ray

scholarly journals Identification of a TeO32− reductase/mycothione reductase from Rhodococcus erythropolis PR4

2020 ◽  
Vol 97 (1) ◽  
Author(s):  
Zachary J Butz ◽  
Alexander Hendricks ◽  
Kanda Borgognoni ◽  
Christopher J Ackerson
Keyword(s):  
Homology Modeling ◽  
Active Site ◽  
Molecular Basis ◽  
Reduction Potential ◽  
Metal Tolerance ◽  
Ph Dependence ◽  
Rhodococcus Erythropolis ◽  
Aromatic Residues ◽  
Fold Excess ◽  
Enzymatic Product

ABSTRACT A Rhodococcus erythropolis bacterium that tolerates normally lethal concentrations of Fe(II), Cu(II), AsO32−, SeO32−, TeO32−, Cd(II) and Zn(II) was identified from an environmental isolate. In characterizing the molecular basis for metal tolerance, a mycothione reductase (Mtr) with remarkable selectivity for TeO32− reduction over SeO32− was identified. In equimolar concentrations of TeO32− and SeO32−, the enzymatic product contains a 7-fold excess of Te. This selectivity is remarkable because the standard reduction potential of SeO32− is 0.20 V more favorable for reduction than TeO32. Selectivity of the enzyme for TeO32− decreases with increasing assay pH. Homology modeling of the enzyme identifies four aromatic residues near the active site, including two histidine residues, that are not present in a related SeO32− preferring reductase. On the basis of more favorable π-interactions for Te than for Se and the pH dependence of the selectivity, the Te-selectivity is attributed in part to these aromatic residues. The resulting Te0 enzymatic product resembles Te nanowires.

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