Functional Adaptation of BabA, the H. pylori ABO Blood Group Antigen Binding Adhesin

• DOI: 10.1126/science.1098801
• Publication Date: 2004-07-22T20:38:37Z
• Authors: Marina Aspholm-Hu...; Giedrius Dailide; Martina Lahmann; Awdhesh Kalia; Dag Ilver; Niamh Roche; Susanne Vikström; Rolf Sjöström; Sara Lindén; Anna Bäckström; Carina Lundberg; Anna Arnqvist; Jafar Mahdavi; Ulf J. Nilsson; Billie Velapatiño; Robert H. Gilman; Markus Gerhard; Teresa Alarcon; Manuel López-Brea; Teruko Nakazawa; James G. Fox; Pelayo Correa; Maria Gloria Domi...; Guillermo I. Pere...; Martin J. Blaser; Staffan Normark; Ingemar Carlstedt; Stefan Oscarson; Susann Teneberg; Douglas E. Berg; Thomas Borén
• Keywords: 0301 basic medicine; Binding Sites; Base Sequence; Helicobacter pylori; Indians, South American; Molecular Sequence Data; Adaptation, Biological; Bacterial Adhesion; ABO Blood-Group System; Helicobacter Infections; Evolution, Molecular; 03 medical and health sciences; Lewis Blood Group Antigens; Phenotype; Gastric Mucosa; Mutation; Peru; Humans; Adhesins, Bacterial; Alleles; Phylogeny; Fucose

Adherence by Helicobacter pylori increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens (generalists), whereas 60% of adherent South American Amerindian strains bind blood group O antigens best (specialists). This specialization coincides with the unique predominance of blood group O in these Amerindians. Strains differed about 1500-fold in binding affinities, and diversifying selection was evident in babA sequences. We propose that cycles of selection for increased and decreased bacterial adherence contribute to babA diversity and that these cycles have led to gradual replacement of generalist binding by specialist binding in blood group O–dominant human populations.