Covalently binds beta-alanine in an ATP-dependent manner to form a thioester bond with its phosphopantetheine group and transfers it to an, as yet, unknown acceptor. May be required for a post- translational protein modification or for post-transcriptional modification of an RNA. . This is the function of AASDH (aminoadipate-semialdehyde dehydrogenase, Ensembl gene identifier ENSG00000157426).