Alignment of the protein sequences Pb, Mc, Nc, and Xd predicted from
the sequences of genes carRA from Phycomyces
blakesleeanus, al-2 (ref. 31; GenBank accession
no. L27652) from Neurospora crassa, crtYB
(ref. 32; accession no. AJ133646) from Xanthophyllomyces
dendrorhous (syn. Rhodomyces dendrorhous and
Phaffia rhodozyma), and carRP (ref. 33;
accession no. AJ250827) from Mucor circinelloides. The
line marks the putative cleavage site in the Phycomyces
sequence at the approximate limit of the lycopene cyclase and phytoene
synthase domains. The black circles locate the mutations in six
Phycomyces color mutants. The arrowheads indicate the
presence of introns in the gene sequence.