1t4a
From Proteopedia
(New page: 200px<br /><applet load="1t4a" size="450" color="white" frame="true" align="right" spinBox="true" caption="1t4a, resolution 2.00Å" /> '''Structure of B. Subt...) |
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| - | [[Image:1t4a.jpg|left|200px]]<br /><applet load="1t4a" size=" | + | [[Image:1t4a.jpg|left|200px]]<br /><applet load="1t4a" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1t4a, resolution 2.00Å" /> | caption="1t4a, resolution 2.00Å" /> | ||
'''Structure of B. Subtilis PurS C2 Crystal Form'''<br /> | '''Structure of B. Subtilis PurS C2 Crystal Form'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Formylglycinamide ribonucleotide amidotransferase (FGAR-AT) catalyzes the | + | Formylglycinamide ribonucleotide amidotransferase (FGAR-AT) catalyzes the conversion of formylglycinamide ribonucleotide (FGAR), ATP, and glutamine to formylglycinamidine ribonucleotide (FGAM), ADP, P(i), and glutamate in the fourth step of the purine biosynthetic pathway. PurL exists in two forms: large PurL (lgPurL) is a single chain, multidomain enzyme of about 1300 amino acids, whereas small PurL (smPurL) contains about 800 amino acids but requires two additional gene products, PurS and PurQ, for activity. smPurL contains the ATP and FGAR binding sites, PurQ is a glutaminase, and the function of PurS is just now becoming understood. We determined the structure of Bacillus subtilis PurS in two different crystal forms P2(1) and C2 at 2.5 and 2.0 A resolution, respectively. PurS forms a tight dimer with a central six-stranded beta-sheet flanked by four helices. In both the P2(1) and the C2 crystal forms, the quaternary structure of PurS is a tetramer. The concave faces of the PurS dimers interact via the C-terminal region to form a twelve-stranded beta-barrel with a hydrophilic core. We used the structure of PurS together with the structure of lgPurL from Salmonella typhimurium to construct a model of the PurS/smPurL/PurQ complex. The HisH (glutaminase) domain of imidazole glycerol phosphate synthetase was used as an additional model of PurQ. The model shows stoichiometry of 2PurS/smPurL/PurQ using a PurS dimer or 4PurS/2smPurL/2PurQ using a PurS tetramer. Both models place key conserved residues at the ATP/FGAR binding site and at a structural ADP binding site. The homology model is consistent with biochemical studies on the reconstituted complex. |
==About this Structure== | ==About this Structure== | ||
| - | 1T4A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis]. Full crystallographic information is available from [http:// | + | 1T4A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T4A OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Anand, R.]] | [[Category: Anand, R.]] | ||
| - | [[Category: Bennett, E | + | [[Category: Bennett, E M.]] |
| - | [[Category: Ealick, S | + | [[Category: Ealick, S E.]] |
| - | [[Category: Hoskins, A | + | [[Category: Hoskins, A A.]] |
| - | [[Category: Sintchak, M | + | [[Category: Sintchak, M D.]] |
[[Category: Stubbe, J.]] | [[Category: Stubbe, J.]] | ||
[[Category: complex formyl glycinamide synthetase]] | [[Category: complex formyl glycinamide synthetase]] | ||
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[[Category: tetramer]] | [[Category: tetramer]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:09:46 2008'' |
Revision as of 13:09, 21 February 2008
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Structure of B. Subtilis PurS C2 Crystal Form
Overview
Formylglycinamide ribonucleotide amidotransferase (FGAR-AT) catalyzes the conversion of formylglycinamide ribonucleotide (FGAR), ATP, and glutamine to formylglycinamidine ribonucleotide (FGAM), ADP, P(i), and glutamate in the fourth step of the purine biosynthetic pathway. PurL exists in two forms: large PurL (lgPurL) is a single chain, multidomain enzyme of about 1300 amino acids, whereas small PurL (smPurL) contains about 800 amino acids but requires two additional gene products, PurS and PurQ, for activity. smPurL contains the ATP and FGAR binding sites, PurQ is a glutaminase, and the function of PurS is just now becoming understood. We determined the structure of Bacillus subtilis PurS in two different crystal forms P2(1) and C2 at 2.5 and 2.0 A resolution, respectively. PurS forms a tight dimer with a central six-stranded beta-sheet flanked by four helices. In both the P2(1) and the C2 crystal forms, the quaternary structure of PurS is a tetramer. The concave faces of the PurS dimers interact via the C-terminal region to form a twelve-stranded beta-barrel with a hydrophilic core. We used the structure of PurS together with the structure of lgPurL from Salmonella typhimurium to construct a model of the PurS/smPurL/PurQ complex. The HisH (glutaminase) domain of imidazole glycerol phosphate synthetase was used as an additional model of PurQ. The model shows stoichiometry of 2PurS/smPurL/PurQ using a PurS dimer or 4PurS/2smPurL/2PurQ using a PurS tetramer. Both models place key conserved residues at the ATP/FGAR binding site and at a structural ADP binding site. The homology model is consistent with biochemical studies on the reconstituted complex.
About this Structure
1T4A is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
A model for the Bacillus subtilis formylglycinamide ribonucleotide amidotransferase multiprotein complex., Anand R, Hoskins AA, Bennett EM, Sintchak MD, Stubbe J, Ealick SE, Biochemistry. 2004 Aug 17;43(32):10343-52. PMID:15301532
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