Phosphonopyruvate decarboxylase PPD

In the framework of SFB380, two projects dealt extensively with acyloin-con-densing ThDP-dependent enzymes such as pyruvate decarboxylase (PDC), ben-zoylformate decarboxylase (BFD), or benzaldehyde lyase (BAL) (see Chapters 2.2.3 and 2.2.7). Another ThDP-dependent decarboxylase, phosphonopyruvate decarboxylase (PPD) from Streptomyces viridochromogenes, became available only recently and was studied in project B21. We wanted to find out whether this PDC-related enzyme could be a valuable tool in the provision of acyloin condensations involving C-P bonds (see Section 2.2.2.23). 

C-P bonds are present in a range of natural compounds, for example, antibiotics. Through a reaction of PEP mutase, phosphoenolpyruvate is converted to phosphonopyruvate, which is the precursor of all natural phosphono compounds. The ThDP-dependent enzyme phosphonopyruvate decarboxylase (PPD) has been discovered in several Streptomycetes and other bacteria [24] its reaction is depicted in Scheme 2.2.2.3. 

Fig. 2.2.2.2 Postulated model of the active site of phosphonopyruvate decarboxylase. PPD from Str. viridochromogenes T0494 (based on the structure of PDC from Zymomonas mobilis [27] and data from analyis of site-directed mutants [25]). The model depicts the start of the catalytic reaction (deprotonation of the reactive C2 atom (yellow) on the thiazolium ring ofThDP...

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