View source for Phosphatase Subfamily Acr2

[[Phosphatase classification|Phosphatase Classification]]: [[Phosphatase_Superfamily_Cys-based_II|Superfamily Cys-based II]]: [[Phosphatase_Family_CDC25|Family CDC25]]: [[Subfamily_Acr2|Subfamily Acr2]]

Prokaryotes and eukaryotes use arsenate reductases of distinct folds. ''E. coli'' uses ArsC, which belongs to [[Phosphatase_Superfamily_Cys-based_III|Superfamily Cys-based III]], the same as [[Phosphatase_Family_LMWPTP|LMWPTP]] and [[Phosphatase_Family_SSU72|SSU72]]. Eukaryotes, particularly fungi, plants and protists, may use ACR2 which have the same fold as [[Phosphatase_Family_CDC25|CDC25]] <cite>yeo09</cite>. However, knocking out ACR2 does not affect arsenic redox status in ''Arabidopsis thaliana'' and ''Saccharomyces cerevisiae'' , which implies the existence of other arsenate reductase(s) in plants and yeast <cite>atha-ar-12</cite>.

=== Arc2  in eukaryotes ===
''Saccharomyces cerevisiae''. Overexpressed in ''E. coli'', [http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000006404 ARR2], the ACR2 gene of  ''Saccharomyces cerevisiae'', was shown to exhibit arsenate reductase activity and complement the arsenate-sensitive phenotype of an ArsC deletion in ''E. coli'' <cite>yeast98 yeast00 yeo09</cite>. The Cx5R motif is required for its catalytic activity as arsenate reductase <cite>yeast01</cite>.

''Arabidopsis thaliana''. Acr2 of ''Arabidopsis thaliana'' was initially characterized as a phosphatase, given the evidences: i) protein structure solved by NMR <cite>atha-phosphatase-04</cite>, ii) recombinant expression in E. coli shows tyrosine phosphatase activity towards artificial substrate <cite>atha-phosphatase-04b</cite>, and iii) overexpression in fission yeast function suggests it is a mitotic accelerator <cite>atha-phosphatase-05</cite>. It has been suggested to play a role in arsenate reduction <cite>atha-ar-06 atha-ar-06b fern05</cite>. However, knocking out ACR2 does not affect arsenic redox status in ''Arabidopsis thaliana'' and ''Saccharomyces cerevisiae'' <cite>atha-ar-12</cite>.

''Pteris vittata'' (fern). The ACR2 of "Pteris vittata" (PvACR2) can suppress the arsenate sensitivity and arsenic hyperaccumulation phenotypes of yeast (''Saccharomyces cerevisiae'') lacking the arsenate reductase gene ACR2 <cite>fern05 fern06</cite>.  However, PvACR2 is unique in that the arginine of catalytic motif Cx5R, previously shown to be essential for phosphatase and reductase activity, is replaced with a serine. 

''Chlamydomonas reinhardtii'' (green alga). ''Chlamydomonas reinhardtii'' has two Acr2s. One of them complement the arsenate-sensitive phenotype of an ArsC deletion in ''E. coli'' <cite>green-alga-11</cite>

=== Reference ===
<biblio>
#yeo09 pmid=19382206
#yeast98 pmid=9812373
#yeast00 pmid=10801893
#yeast01 pmid=11461905
#atha-phosphatase-04 pmid=15329414
#atha-phosphatase-04b pmid=15329414
#atha-phosphatase-05 pmid=15720653
#atha-ar-06 pmid=16507083
#atha-ar-06b pmid=16567632
#atha-ar-12 pmid=22879969
#fern05 pmid=15834011
#fern06 pmid=16766666
#green-alga-11 pmid=22125913
</biblio>