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PDBsum entry 1hxj

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protein Protein-protein interface(s) links
Hydrolase PDB id
1hxj
Jmol
Contents
Protein chains
490 a.a. *
Waters ×909
* Residue conservation analysis
PDB id:
1hxj
Name: Hydrolase
Title: Crystal structure of the maize zm-p60.1 beta-glucosidase
Structure: Beta-glucosidase. Chain: a, b. Synonym: gentiobiase, cellobiase, beta-d-glucoside glucohydrolase. Engineered: yes
Source: Zea mays. Organism_taxid: 4577. Strain: cv. Mutin. Tissue: coleoptile. Organelle: chloroplast. Expressed in: escherichia coli. Expression_system_taxid: 562.
Biol. unit: Dimer (from PQS)
Resolution:
2.05Å     R-factor:   0.168     R-free:   0.229
Authors: J.Vevodova,X.-D.Su,J.Marek,B.Brzobohaty
Key ref: J.Zouhar et al. (2001). Insights into the functional architecture of the catalytic center of a maize beta-glucosidase Zm-p60.1. Plant Physiol, 127, 973-985. PubMed id: 11706179
Date:
15-Jan-01     Release date:   21-Jan-03    
PROCHECK
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 Headers
 References

Protein chains
Pfam   ArchSchema ?
P49235  (BGLC_MAIZE) -  4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase 1, chloroplastic
Seq:
Struc:
 
Seq:
Struc:
566 a.a.
490 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class 2: E.C.3.2.1.182  - 4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction:
1. (2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl beta-D-glucopyranoside + H2O = 2,4-dihydroxy-7-methoxy-2H-1,4- benzoxazin-3(4H)-one + D-glucose
2. (2R)-4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl beta-D- glucopyranoside + H2O = 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one + D-glucose
(2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl beta-D-glucopyranoside
+ H(2)O
= 2,4-dihydroxy-7-methoxy-2H-1,4- benzoxazin-3(4H)-one
+ D-glucose
(2R)-4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl beta-D- glucopyranoside
+ H(2)O
= 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one
+ D-glucose
   Enzyme class 3: E.C.3.2.1.21  - Beta-glucosidase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Hydrolysis of terminal, non-reducing beta-D-glucose residues with release of beta-D-glucose.
Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     plastid   2 terms 
  Biological process     metabolic process   3 terms 
  Biochemical function     hydrolase activity     4 terms  

 

 
    reference    
 
 
Plant Physiol 127:973-985 (2001)
PubMed id: 11706179  
 
 
Insights into the functional architecture of the catalytic center of a maize beta-glucosidase Zm-p60.1.
J.Zouhar, J.Vévodová, J.Marek, J.Damborský, X.D.Su, B.Brzobohatý.
 
  ABSTRACT  
 
The maize (Zea mays) beta-glucosidase Zm-p60.1 has been implicated in regulation of plant development by the targeted release of free cytokinins from cytokinin-O-glucosides, their inactive storage forms. The crystal structure of the wild-type enzyme was solved at 2.05-A resolution, allowing molecular docking analysis to be conducted. This indicated that the enzyme specificity toward substrates with aryl aglycones is determined by aglycone aromatic system stacking with W373, and interactions with edges of F193, F200, and F461 located opposite W373 in a slot-like aglycone-binding site. These aglycone-active site interactions recently were hypothesized to determine substrate specificity in inactive enzyme substrate complexes of ZM-Glu1, an allozyme of Zm-p60.1. Here, we test this hypothesis by kinetic analysis of F193I/Y/W mutants. The decreased K(m) of all mutants confirmed the involvement of F193 in determining enzyme affinity toward substrates with an aromatic aglycone. It was unexpected that a 30-fold decrease in k(cat) was found in F193I mutant compared with the wild type. Kinetic analysis and computer modeling demonstrated that the F193-aglycone-W373 interaction not only contributes to aglycone recognition as hypothesized previously but also codetermines catalytic rate by fixing the glucosidic bond in an orientation favorable for attack by the catalytic pair, E186 and E401. The catalytic pair, assigned initially by their location in the structure, was confirmed by kinetic analysis of E186D/Q and E401D/Q mutants. It was unexpected that the E401D as well as C205S and C211S mutations dramatically impaired the assembly of a catalysis-competent homodimer, suggesting novel links between the active site structure and dimer formation.
 

Literature references that cite this PDB file's key reference

  PubMed id Reference
20490603 J.R.Ketudat Cairns, and A.Esen (2010).
β-Glucosidases.
  Cell Mol Life Sci, 67, 3389-3405.  
19682295 R.Sánchez-Pérez, K.Jørgensen, M.S.Motawia, F.Dicenta, and B.L.Møller (2009).
Tissue and cellular localization of individual beta-glycosidases using a substrate-specific sugar reducing assay.
  Plant J, 60, 894-906.  
18615662 A.D.Hill, and P.J.Reilly (2008).
Computational analysis of glycoside hydrolase family 1 specificities.
  Biopolymers, 89, 1021-1031.  
19016858 R.Dopitová, P.Mazura, L.Janda, R.Chaloupková, P.Jerábek, J.Damborský, T.Filipi, N.S.Kiran, and B.Brzobohatý (2008).
Functional analysis of the aglycone-binding site of the maize beta-glucosidase Zm-p60.1.
  FEBS J, 275, 6123-6135.  
17503162 M.León, P.Isorna, M.Menéndez, J.Sanz-Aparicio, and J.Polaina (2007).
Comparative study and mutational analysis of distinctive structural elements of hyperthermophilic enzymes.
  Protein J, 26, 435-444.  
12487426 Y.Bhatia, S.Mishra, and V.S.Bisaria (2002).
Microbial beta-glucosidases: cloning, properties, and applications.
  Crit Rev Biotechnol, 22, 375-407.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.