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 procambium, lateral root primordia, vascular tissues of cotyledons, leaves and stems, shoot apical meristem, axillary buds, young inflorescences, fruit abscission zones and basal part of ovules. No visible phenotype under normal growth conditions; due to the redundancy with other LOG proteins. Belongs to the LOG family.