Disaccharide Digestion: Clinical and Molecular Aspects Claudia C. Robayo–Torres, Roberto Quezada–Calvillo, Buford L. Nichols  Clinical Gastroenterology and Hepatology  Volume 4, Issue 3, Pages 276-287 (March 2006) DOI: 10.1016/j.cgh.2005.12.023 Copyright © 2006 American Gastroenterological Association Institute Terms and Conditions

Figure 1 Human LPH gene and the LPH precursor. (A) The currently accepted location and orientation of the human LPH structural gene are indicated. The length of the promoter, as defined by the location of known sequences or nucleotides with a regulatory effect on the transcription of the structural gene, is shown at the same scale as the structural region. The 3′ extreme of the MCM6 gene is shown by the dotted lines. The amplification is shown underneath the location of known regulatory or protein binding sequences in the close promoter region; the TATA signal is indicated. Single nucleotide polymorphisms with an effect on the expression of LPH are shown as red vertical lines and neutral ones are shown with blue vertical lines. (B) Linear representation of the location of the subunits and domains of the LPH synthesized precursor. Blue triangles, location and type of single amino-acid variations without reported biologic effect; vertical blue lines, potential glycosylation sites. GlyHyd1, sequences with homology to consensus sequences for domains of the Family 1 of glycohydrolase proteins; as1 and as2, location of amino-acid residues involved in the putative active sites; pd, putative proton donor involved in the active site; Nu, putative nucleophil involved in the active site; Sig, signal sequence; tm, transmembrane domain. Clinical Gastroenterology and Hepatology 2006 4, 276-287DOI: (10.1016/j.cgh.2005.12.023) Copyright © 2006 American Gastroenterological Association Institute Terms and Conditions

Figure 2 SI gene and the SI protein. (A) The currently accepted location and orientation of the human SI structural gene are indicated. The locations of known regulatory or protein-binding sequences in the promoter region and the TATA signal are indicated in the amplification shown underneath. (B) Linear representation of the location of subunits and domains of the SI complex. Blue triangles, location and type of single amino-acid variations without reported biologic effect; red triangles, location and type of single amino-acid variations with reported biologic effect; white triangle, identified site of trypsin cleavage; vertical blue lines, potential glycosylation sites. GlyHyd31, sequences with homology to consensus sequences for domains of the Family 31 of glycohydrolase proteins; Cyt, cytoplasmic domain; tm, transmembrane domain; s/t, serine- and threonine-rich region; tff, Tre-foil P-type domain; widmne, putative active site. Clinical Gastroenterology and Hepatology 2006 4, 276-287DOI: (10.1016/j.cgh.2005.12.023) Copyright © 2006 American Gastroenterological Association Institute Terms and Conditions