ClustalW protein sequence alignment of SLC4A9 with paralogous proteins described in the literature or discovered in silico in this report, in order of decreasing similarity. Proteins shown: SLC4A9 (isoform I); SLC4A8/HNBC3 (BAA34459.1); SLC4A4/SLC4A5/HNBC1 (AAD42020.1); SLC4A6/SLC4A7/HNBC2 (AAD38322.1); NBC4 (AAG18492) and HNBC7 (translated Unigene cluster Hs.211115 and translations of SeqHelp-identified NBC-homologous exons from AC018411.3, AL139426.1, and AC064816.1). The known 990 amino acid carboxy-terminal portion of SLC4A9 isoform I is shown, preceded by spaces. The longest publicly available protein sequence was selected for SLC4A4/A5, SLC4A6/A7 and SLC4A8. Spaces indicate undetermined amino-terminal portions of SLC4A9 and undetermined amino-terminal and carboxy-terminal portions in the currently available HNBC7 sequence. Dashes indicate known gaps or known absence of sequences at indicated positions. White on black background, identity across most or all of the proteins shown. Black on dark gray background, strong similarity in the type of amino acid at position shown. Black on light gray background, weak similarity in the type of amino acid at position shown. Vertical bars indicate exon boundaries on the SLC4A9 sequence. Exon numbers and exon fragment designations are immediately to the right of each bar. Each bar is directly over the first amino acid of the exon or fragment. For phase 1 introns, the amino acid whose codon is broken by the intron or breakpoint is considered to follow the intron or breakpoint; for phase 2, it is considered to precede it. On the SLC4A9 sequence, the 12 transmembrane segments are in red. Intracellular serine, threonine and tyrosine residues predicted by NetPhos v.2.0  as putative phosphorylation sites with a score of 0.5 or above are in blue.