Comparison of cDNA and DNA sequences of human CBWD genes. CBWD1, CBWD2, CBWD3, and CBWD4P represent cobalamin synthetase W domain-containing sequences from 9pter, 2qFus, 9q13, and 9p11.2 (or another block in 9q13, see Fig. 1), respectively. Sequences of four transcripts are compared with the genomic sequences. Only the coding portions are shown. AF257330 is a cDNA sequence from GenBank (Shi et al. 2001). AF452722 is a sequence we obtained by PCR amplification of human brain Marathon-Ready cDNAs. A cDNA sequence from GenBank, BC005996 (Mammalian gene collection, http://mgc.nci.nih.gov) and an EST contiguous sequence assembled from EST sequences AL540640, AL545680, and AL571299 match the 9pter sequence exactly and are therefore not shown. Blue residues are identical to AF257330; black residues differ from it. Dashed lines indicate incomplete sequence information. Arrows indicate exon boundaries. Predicted amino acid sequences are indicated below the nucleotide sequences. Accession numbers for genomic copies as in Figure 1.