PMID- 22081394
OWN - NLM
STAT- MEDLINE
DCOM- 20120306
LR  - 20211021
IS  - 1098-5530 (Electronic)
IS  - 0021-9193 (Print)
IS  - 0021-9193 (Linking)
VI  - 194
IP  - 2
DP  - 2012 Jan
TI  - Structural insights into the catalytic mechanism of Escherichia coli 
      selenophosphate synthetase.
PG  - 499-508
LID - 10.1128/JB.06012-11 [doi]
AB  - Selenophosphate synthetase (SPS) catalyzes the synthesis of selenophosphate, the 
      selenium donor for the biosynthesis of selenocysteine and 2-selenouridine 
      residues in seleno-tRNA. Selenocysteine, known as the 21st amino acid, is then 
      incorporated into proteins during translation to form selenoproteins which serve 
      a variety of cellular processes. SPS activity is dependent on both Mg(2+) and 
      K(+) and uses ATP, selenide, and water to catalyze the formation of AMP, 
      orthophosphate, and selenophosphate. In this reaction, the gamma phosphate of ATP 
      is transferred to the selenide to form selenophosphate, while ADP is hydrolyzed 
      to form orthophosphate and AMP. Most of what is known about the function of SPS 
      has derived from studies investigating Escherichia coli SPS (EcSPS) as a model 
      system. Here we report the crystal structure of the C17S mutant of SPS from E. 
      coli (EcSPS(C17S)) in apo form (without ATP bound). EcSPS(C17S) crystallizes as a 
      homodimer, which was further characterized by analytical ultracentrifugation 
      experiments. The glycine-rich N-terminal region (residues 1 through 47) was found 
      in the open conformation and was mostly ordered in both structures, with a 
      magnesium cofactor bound at the active site of each monomer involving conserved 
      aspartate residues. Mutating these conserved residues (D51, D68, D91, and D227) 
      along with N87, also found at the active site, to alanine completely abolished 
      AMP production in our activity assays, highlighting their essential role for 
      catalysis in EcSPS. Based on the structural and biochemical analysis of EcSPS 
      reported here and using information obtained from similar studies done with SPS 
      orthologs from Aquifex aeolicus and humans, we propose a catalytic mechanism for 
      EcSPS-mediated selenophosphate synthesis.
FAU - Noinaj, Nicholas
AU  - Noinaj N
AD  - National Institute of Diabetes and Digestive and Kidney Diseases, National 
      Institutes of Health, Bethesda, Maryland, USA. noinajn@niddk.nih.gov
FAU - Wattanasak, Rut
AU  - Wattanasak R
FAU - Lee, Duck-Yeon
AU  - Lee DY
FAU - Wally, Jeremy L
AU  - Wally JL
FAU - Piszczek, Grzegorz
AU  - Piszczek G
FAU - Chock, P Boon
AU  - Chock PB
FAU - Stadtman, Thressa C
AU  - Stadtman TC
FAU - Buchanan, Susan K
AU  - Buchanan SK
LA  - eng
SI  - PDB/3U0O
GR  - Intramural NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Intramural
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20111111
PL  - United States
TA  - J Bacteriol
JT  - Journal of bacteriology
JID - 2985120R
RN  - 0 (2-selenouridine)
RN  - 0 (Organoselenium Compounds)
RN  - 0 (seleno-tRNA)
RN  - 0CH9049VIS (Selenocysteine)
RN  - 9014-25-9 (RNA, Transfer)
RN  - EC 2.7.- (Phosphotransferases)
RN  - EC 2.7.9.3 (selenophosphate synthetase)
RN  - WHI7HQ7H85 (Uridine)
SB  - IM
MH  - Catalysis
MH  - Cloning, Molecular
MH  - Crystallization
MH  - Escherichia coli/*enzymology
MH  - Gene Expression Regulation, Bacterial/*physiology
MH  - Gene Expression Regulation, Enzymologic/physiology
MH  - Models, Molecular
MH  - Mutagenesis
MH  - Organoselenium Compounds
MH  - Phosphotransferases/genetics/*metabolism
MH  - Protein Conformation
MH  - RNA, Transfer/biosynthesis
MH  - Selenocysteine/biosynthesis
MH  - Uridine/analogs & derivatives/biosynthesis
PMC - PMC3256651
EDAT- 2011/11/15 06:00
MHDA- 2012/03/07 06:00
PMCR- 2012/07/01
CRDT- 2011/11/15 06:00
PHST- 2011/11/15 06:00 [entrez]
PHST- 2011/11/15 06:00 [pubmed]
PHST- 2012/03/07 06:00 [medline]
PHST- 2012/07/01 00:00 [pmc-release]
AID - JB.06012-11 [pii]
AID - 6012-11 [pii]
AID - 10.1128/JB.06012-11 [doi]
PST - ppublish
SO  - J Bacteriol. 2012 Jan;194(2):499-508. doi: 10.1128/JB.06012-11. Epub 2011 Nov 11.