Fig. 5. ix DNA sequence and predicted protein product. (A) DNA and protein sequences. The ix DNA sequence (GenBank Accession Number, AF491289) is shown with the predicted protein sequence in single-letter code below the corresponding nucleotides. 5' RACE experiments defined the start of the 5' UTR (underlined), and 3' RACE experiments determined the 3' end of the mRNA (position at which polyadenylation begins underlined). The putative upstream exon suggested by results of RT-PCR experiments is indicated in bold. (B) Schematic of the predicted ix protein. The asterisk indicates the stop codon inserted in the 3GBG* knockout construct. The gray and black boxes represent regions of the ix protein with sequence similarity to known proteins and ESTs. (C) Sequence alignment of the N-terminal region of the ix protein (gray in B) with the mammalian SYT and C. elegans sur-2 proteins. The consensus sequence is shown below. (D) Sequence alignment of a region of the ix protein (black in B) with the predicted proteins of human and mouse EST sequences. The consensus sequence is shown below.