2011.08.23,Professors Chen Yuxing and Zhou Congzhao Published a paper in Journal of Biological Chemistry

  • 2011.08.23,Professors Chen Yuxing and Zhou Congzhao published a paper entitled ”tructural and enzymatic characterization of a Streptococcal ATP/diadenosine polyphosphate and phosphodiester hydrolase Spr1479/SapH”in  Journal of Biological Chemistry

    Author:Jiang Yongliang#、Zhang Junwei#、Yu Weili、Chen Wang、Zhang Cenchen、Cecile Frolet、Anne-Marie Di Guilmi、Thierry Vernet、Zhou Congzhao、Chen Yuxing

    Abstract

    Spr1479 from Streptococcus pneumoniae R6 is a 33-kDa hypothetical protein of unknown function. Here, we determined the crystal structures of its apo-form at 1.90 Å, and complex forms with inorganic phosphate and adenosine monophosphate (AMP) at 2.30 Å and 2.20 Å, respectively. The core structure of Spr1479 adopts a four-layered α-β-β-α sandwich fold, with Fe3+ and Mn2+ coordinated at the binuclear center of the active site (similar to metallophosphoesterases). Enzymatic assays show that in addition to phosphodiesterase activity towards bis-(p-nitrophenyl) phosphate, Spr1479 has hydrolase activity towards diadenosine polyphosphate (ApnA) and ATP. Residues that coordinate with the two metals are indispensable for both activities. By contrast, the Streptococci-specific residue Trp67, which binds to phosphate in the two complex structures, is indispensable for the ATP/ApnA hydrolase activity only. Moreover, the AMP-binding pocket is exclusively conserved in all Streptococci. Therefore, we named the protein SapH, for Streptococcal ATP/ApnA and phosphodiester hydrolase.

     

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