{PDOC00834}
{PS01087; RADICAL_ACTIVATING}
{BEGIN}
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* Radical activating enzymes signature *
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In Escherichia  coli  and  related  bacteria, the pflA protein (or act) [1] is
involved (EC 1.97.1.4) in the activation of pyruvate formate-lyase (gene pflB)
under anaerobic  conditions by generation of an organic free radical, using S-
adenosylmethionine and reduced flavodoxin as cosubstrates to produce 5'-deoxy-
adenosine. A protein highly similar to pflA and  termed  pflC  [2] is probably
involved in the activation of a second pyruvate format  lyase (gene pflD). The
pflA/C proteins belong to a family that also includes phage T4 and Escherichia
coli nrdG which are involved [3] in the generation of the free radical for the
anaerobic ribonucleoside-triphosphate  reductase  (gene  nrdD   or sunY). This
family also includes:

 - Escherichia coli hypothetical protein yjjW.
 - Haemophilus influenzae hypothetical protein HI0520.
 - Methanococcus jannaschii hypothetical protein MJ0021.

All these  proteins  possess,  in their N-terminal section, a highly conserved
region which  contains  three  clustered  cysteines  which are involved in the
binding of  a 4Fe4S iron-sulfur cluster [4]. We use this region as a signature
pattern.

-Consensus pattern: [GVPS]-x-[GKS]-x-[KRS]-x(3)-[FL]-x(2)-G-x(0,1)-C-x(3)-C-
                    x(2)-C-x-[NLF]
                    [The 3 C's are 4Fe-4S ligands]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Last update: December 2004 / Pattern and text revised.

[ 1] Roedel W., Plaga W., Frank R., Knappe J.
     Eur. J. Biochem. 177:153-158(1988).
[ 2] Reizer J., Reizer A., Saier M.H. Jr.
     "Novel phosphotransferase system genes revealed by bacterial genome
     analysis--a gene cluster encoding a unique Enzyme I and the proteins
     of a fructose-like permease system."
     Microbiology 141:961-971(1995).
     PubMed=7773398
[ 3] Sun X., Eliasson R., Pontis E., Andersson J., Buist G., Sjoeberg B.-M.,
     Reichard P.
     "Generation of the glycyl radical of the anaerobic Escherichia coli
     ribonucleotide reductase requires a specific activating enzyme."
     J. Biol. Chem. 270:2443-2446(1995).
     PubMed=7852304
[ 4] Tamarit J., Gerez C., Meier C., Mulliez E., Trautwein A.,
     Fontecave M.
     "The activating component of the anaerobic ribonucleotide reductase
     from Escherichia coli. An iron-sulfur center with only three
     cysteines."
     J. Biol. Chem. 275:15669-15675(2000).
     PubMed=10821845

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