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 can also use benzyladenine riboside 5'-monophosphste as substrate. Optimum pH is 5.4. Expressed in roots and shoots. Detected in vascular tissues of roots, cotyledons, and leaves, axillary buds, immature and mature flowers, fruit abscission zones and ovules. No visible phenotype under normal growth conditions; due to the redundancy with other LOG proteins. Belongs to the LOG family.