PMID- 12450384
OWN - NLM
STAT- MEDLINE
DCOM- 20030110
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 41
IP  - 48
DP  - 2002 Dec 3
TI  - Crystal structures of human GAR Tfase at low and high pH and with substrate 
      beta-GAR.
PG  - 14206-15
AB  - Glycinamide ribonucleotide transformylase (GAR Tfase) is a key folate-dependent 
      enzyme in the de novo purine biosynthesis pathway and, as such, has been the 
      target for antitumor drug design. Here, we describe the crystal structures of the 
      human GAR Tfase (purN) component of the human trifunctional protein 
      (purD-purM-purN) at various pH values and in complex with its substrate. Human 
      GAR Tfase exhibits pH-dependent enzyme activity with its maximum around pH 7.5-8. 
      Comparison of unliganded human GAR Tfase structures at pH 4.2 and pH 8.5 reveals 
      conformational differences in the substrate binding loop, which at pH 4.2 
      occupies the binding cleft and prohibits substrate binding, while at pH 8.5 is 
      permissive for substrate binding. The crystal structure of GAR Tfase with its 
      natural substrate, beta-glycinamide ribonucleotide (beta-GAR), at pH 8.5 confirms 
      this conformational isomerism. Surprisingly, several important structural 
      differences are found between human GAR Tfase and previously reported E. coli GAR 
      Tfase structures, which have been used as the primary template for drug design 
      studies. While the E. coli structure gave valuable insights into the active site 
      and formyl transfer mechanism, differences in structure and inhibition between 
      the bacterial and mammalian enzymes suggest that the human GAR Tfase structure is 
      now the appropriate template for the design of anti-cancer agents.
FAU - Zhang, Yan
AU  - Zhang Y
AD  - Department of Molecular Biology, The Skaggs Institute for Chemical Biology, The 
      Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 
      92037, USA.
FAU - Desharnais, Joel
AU  - Desharnais J
FAU - Greasley, Samantha E
AU  - Greasley SE
FAU - Beardsley, G Peter
AU  - Beardsley GP
FAU - Boger, Dale L
AU  - Boger DL
FAU - Wilson, Ian A
AU  - Wilson IA
LA  - eng
SI  - PDB/1MEJ
SI  - PDB/1MEN
SI  - PDB/1MEO
GR  - P01 CA63536/CA/NCI NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Bacterial Proteins)
RN  - 0 (Multienzyme Complexes)
RN  - 0 (Peptide Fragments)
RN  - 0 (Ribonucleotides)
RN  - 0 (glycinamide ribonucleotide)
RN  - 935E97BOY8 (Folic Acid)
RN  - EC 2.1.2.- (Hydroxymethyl and Formyl Transferases)
RN  - EC 2.1.2.2 (Phosphoribosylglycinamide Formyltransferase)
RN  - EC 6.3.- (Carbon-Nitrogen Ligases)
RN  - EC 6.3.4.13 (GART protein, human)
RN  - TE7660XO1C (Glycine)
SB  - IM
MH  - Bacterial Proteins/chemistry/metabolism
MH  - Binding Sites
MH  - Carbon-Nitrogen Ligases
MH  - Crystallography, X-Ray
MH  - Dimerization
MH  - Enzyme Activation
MH  - Escherichia coli/enzymology
MH  - Folic Acid/chemistry/metabolism
MH  - Glycine/*analogs & derivatives/*chemistry/metabolism
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Hydroxymethyl and Formyl Transferases/*chemistry/metabolism
MH  - Kinetics
MH  - Multienzyme Complexes/chemistry/metabolism
MH  - Peptide Fragments/chemistry/metabolism
MH  - Phosphoribosylglycinamide Formyltransferase
MH  - Ribonucleotides/*chemistry/metabolism
MH  - Substrate Specificity
EDAT- 2002/11/27 04:00
MHDA- 2003/01/11 04:00
CRDT- 2002/11/27 04:00
PHST- 2002/11/27 04:00 [pubmed]
PHST- 2003/01/11 04:00 [medline]
PHST- 2002/11/27 04:00 [entrez]
AID - bi020522m [pii]
AID - 10.1021/bi020522m [doi]
PST - ppublish
SO  - Biochemistry. 2002 Dec 3;41(48):14206-15. doi: 10.1021/bi020522m.