Cytokinin-activating enzyme working in the direct activation pathway. Phosphoribohydrolase that converts inactive cytokinin nucleotides to the biologically active free-base forms. H2O + N(6)-(dimethylallyl)adenosine 5'-phosphate = D-ribose 5-phosphate + N(6)-dimethylallyladenine 9-ribosyl-trans-zeatin 5'-phosphate + H2O = D-ribose 5-phosphate + trans-zeatin Optimum pH is 6.5. Expressed in roots and shoots. Detected in root hairs. No visible phenotype under normal growth conditions; due to the redundancy with other LOG proteins. Belongs to the LOG family.