Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) as sulfonate donor to specifically catalyze the sulfate conjugation of brassinosteroids, including castasterone (CS), brassinolide (BL), related 24-epimers, and the naturally occurring (22R, 23R)-28-homobrassinosteroids. No activity on phenolic acids, desulfo-glucosinolates, flavonoids, steroids, gibberellic acids, cytokinins, phenylpropanoids, hydroxyjasmonates and coumarins. Expressed in roots. Down-regulated by trans-zeatin. Belongs to the sulfotransferase 1 family.