PDBsum entry 1w6f

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Transferase PDB id
Protein chains
273 a.a. *
ISZ ×4
Waters ×718
* Residue conservation analysis
PDB id:
Name: Transferase
Title: Arylamine n-acetyltransferase from mycobacterium smegmatis with the anti-tubercular drug isoniazid bound in the active site.
Structure: Arylamine n-acetyltransferase. Chain: a, b, c, d. Engineered: yes. Other_details: isoniazid
Source: Mycobacterium smegmatis. Organism_taxid: 1772. Expressed in: escherichia coli. Expression_system_taxid: 469008.
2.10Å     R-factor:   0.182     R-free:   0.219
Authors: J.Sandy,S.Holton,E.Fullham,E.Sim,M.E.M.Noble
Key ref:
J.Sandy et al. (2005). Binding of the anti-tubercular drug isoniazid to the arylamine N-acetyltransferase protein from Mycobacterium smegmatis. Protein Sci, 14, 775-782. PubMed id: 15722451 DOI: 10.1110/ps.041163505
17-Aug-04     Release date:   23-Feb-05    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
O86309  (NAT_MYCSM) -  Arylamine N-acetyltransferase
275 a.a.
273 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.  - Arylamine N-acetyltransferase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Acetyl-CoA + an arylamine = CoA + an N-acetylarylamine
Bound ligand (Het Group name = ISZ)
matches with 54.00% similarity
= CoA
+ N-acetylarylamine
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     cytoplasm   1 term 
  Biological process     metabolic process   1 term 
  Biochemical function     transferase activity     4 terms  


DOI no: 10.1110/ps.041163505 Protein Sci 14:775-782 (2005)
PubMed id: 15722451  
Binding of the anti-tubercular drug isoniazid to the arylamine N-acetyltransferase protein from Mycobacterium smegmatis.
J.Sandy, S.Holton, E.Fullam, E.Sim, M.Noble.
Isoniazid is a frontline drug used in the treatment of tuberculosis (TB). Isoniazid is a prodrug, requiring activation in the mycobacterial cell by the catalase/peroxidase activity of the katG gene product. TB kills two million people every year and the situation is getting worse due to the increase in prevalence of HIV/AIDS and emergence of multidrug-resistant strains of TB. Arylamine N-acetyltransferase (NAT) is a drug-metabolizing enzyme (E.C. NAT can acetylate isoniazid, transferring an acetyl group from acetyl coenzyme A onto the terminal nitrogen of the drug, which in its N-acetylated form is therapeutically inactive. The bacterium responsible for TB, Mycobacterium tuberculosis, contains and expresses the gene encoding the NAT protein. Isoniazid binds to the NAT protein from Salmonella typhimurium and we report here the mode of binding of isoniazid in the NAT enzyme from Mycobacterium smegmatis, closely related to the M. tuberculosis and S. typhimurium NAT enzymes. The mode of binding of isoniazid to M. smegmatis NAT has been determined using data collected from two distinct crystal forms. We can say with confidence that the observed mode of binding of isoniazid is not an artifact of the crystallization conditions used. The NAT enzyme is active in mycobacterial cells and we propose that isoniazid binds to the NAT enzyme in these cells. NAT activity in M. tuberculosis is likely therefore to modulate the degree of activation of isoniazid by other enzymes within the mycobacterial cell. The structure of NAT with isoniazid bound will facilitate rational drug design for anti-tubercular therapy.
  Selected figure(s)  
Figure 1.
Figure 1. Schematic to show activation and inactivation of INH. INH is a prodrug and requires activation by the catalase peroxidase protein (the KatG gene product). The NAT enzymes can N-acetylate INH, rendering the drug therapeutically inactive. The asterisk next to the terminal nitrogen in the active form of INH denotes a range of oxidized species (Bodiguel et al. 2001).
Figure 4.
Figure 4. Orientation of INH in the active site of the NAT enzyme. Electron density can be clearly seen for INH in this omit map contoured at 1.5 . The active site triad residues (Cys70-His110-Asp127) are shown in ball-and-stick format and the associated electron density is shaded in blue. The INH molecule is also shown in ball-and-stick format with the associated electron density shown colored in pink. The backbone is shown in ribbon format. This figure was produced using AESOP.
  The above figures are reprinted by permission from the Protein Society: Protein Sci (2005, 14, 775-782) copyright 2005.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21157591 H.Cong, C.R.Li, S.F.Xue, Z.Tao, Q.J.Zhu, and G.Wei (2011).
Cucurbituril-resisted acylation of the anti-tuberculosis drug isoniazid via a supramolecular strategy.
  Org Biomol Chem, 9, 1041-1046.  
20017673 A.Alfirevic, Z.Alfirevic, and M.Pirmohamed (2010).
Pharmacogenetics in reproductive and perinatal medicine.
  Pharmacogenomics, 11, 65-79.  
20930369 A.Oda, K.Kobayashi, and O.Takahashi (2010).
Computational study of the three-dimensional structure of N-acetyltransferase 2-acetyl coenzyme a complex.
  Biol Pharm Bull, 33, 1639-1643.  
19636684 E.Fullam, A.Kawamura, H.Wilkinson, A.Abuhammad, I.Westwood, and E.Sim (2009).
Comparison of the Arylamine N-acetyltransferase from Mycobacterium marinum and Mycobacterium tuberculosis.
  Protein J, 28, 281-293.  
19319854 K.Horváti, G.Mezo, N.Szabó, F.Hudecz, and S.Bosze (2009).
Peptide conjugates of therapeutically used antitubercular isoniazid-design, synthesis and antimycobacterial effect.
  J Pept Sci, 15, 385-391.  
19670211 R.Koike, A.Kidera, and M.Ota (2009).
Alteration of oligomeric state and domain architecture is essential for functional transformation between transferase and hydrolase with the same scaffold.
  Protein Sci, 18, 2060-2066.  
18795795 A.L.Sikora, B.A.Frankel, and J.S.Blanchard (2008).
Kinetic and chemical mechanism of arylamine N-acetyltransferase from Mycobacterium tuberculosis.
  Biochemistry, 47, 10781-10789.  
18680471 E.Sim, J.Sandy, D.Evangelopoulos, E.Fullam, S.Bhakta, I.Westwood, A.Krylova, N.Lack, and M.Noble (2008).
Arylamine N-acetyltransferases in mycobacteria.
  Curr Drug Metab, 9, 510-519.  
17428149 E.Sim, I.Westwood, and E.Fullam (2007).
Arylamine N-acetyltransferases.
  Expert Opin Drug Metab Toxicol, 3, 169-184.  
17374145 I.M.Westwood, and E.Sim (2007).
Kinetic characterisation of arylamine N-acetyltransferase from Pseudomonas aeruginosa.
  BMC Biochem, 8, 3.  
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.