Biochemistry. In the article “Characterization of soluble forms of nonchimeric type V adenylyl cyclases,” by Klaus Scholich, Ann J. Barbier, Jason B. Mullenix, and Tarun B. Patel, which appeared in number 7, April 1, 1997, of Proc. Natl. Acad. Sci. USA (94, 2915–2920), the authors request that the following changes be noted in the amino acid linker sequence on page 2915. The last sentence of the first paragraph in the “Methods” section should read: [sequence, AAAGGMPPAAAGGM] instead of [sequence, AAAGGM(PPAAAGGM)₂].