BACTERIAL NONSPECIFIC ACID PHOSPHOHYDROLASES - PHYSIOLOGY, EVOLUTION AND USE AS TOOLS IN MICROBIAL BIOTECHNOLOGY

Bacterial nonspecific acid phosphohydrolases (NSAPs) are secreted enzy mes, produced as soluble periplasmic proteins or as membrane-bound lip oproteins, that are usually able to dephosphorylate a broad array of s tructurally unrelated substrates and exhibit optimal catalytic activit y at-acidic to neutral pH values. Bacterial NSAPs are monomeric or oli gomeric proteins containing polypeptide components with an M-r of 25-3 0 kDa. On the basis of amino acid sequence relatedness, three differen t molecular families of NSAPs can be distinguished, indicated as molec ular class A, B and C, respectively. Members of each class share some common biophysical and functional features, but may also exhibit funct ional differences. NSAPs have been detected in several microbial taxa, and enzymes of different classes can be produced by the same bacteria l species. Structural and phyletic relationships exist among the vario us bacterial NSAPs and some other bacterial and eucaryotic phosphohydr olases. Current knowledge on bacterial NSAPs is reviewed, together wit h analytical tools that may be useful for their characterization. An o verview is also presented concerning the use of bacterial NSAPs in bio technology.