In [7], Kuniba, Okado and Yamada proved that the transition matrix of a PBW-type basis of the positive-half of the quantized universal enveloping algebra U-q(g) coincides with a matrix of the intertwiner between certain irreducible modules over the quantized coordinate ring A(q)(g) introduced by Soibelman [13]. In the present article, we give a new proof of their result, by using representation theory of the q-boson algebra, and the Drinfeld pairing of U-q(g). (C) 2016 Elsevier Inc. All rights reserved.