Pectin lyase fold/virulence factor <p>Microbial pectin and pectate lyases are virulence factors that degrade the pectic components of the plant cell wall [<cite idref="PUB00014172"/>]. When the backbone of pectin is methylated it is known as pectin and is cleaved by pectin lyase, and when it is demethylated it is known as pectate and is cleaved by pectate lyase. Pectin lyase from <taxon tax_id="5061">Aspergillus niger</taxon> displays a single-stranded, right-handed parallel beta-helix topology (<db_xref db="INTERPRO" dbkey="IPR006626"/>), where each coil contains three beta-strands and three turn regions. Several other virulence factors share this beta-helix topology, although they vary in the number of coils, including bacterial pectate lyases, fungal and bacterial galacturonases (such as rhamnogalacturonase and polygalacturonase), chrondroitinase B from <taxon tax_id="239">Flavobacterium sp.</taxon>, iota-carrageenase from <taxon tax_id="232">Alteromonas sp.</taxon>, pectin methylesterase (PemA), P22 tailspike protein from <taxon tax_id="10754">Enterobacteria phage P22</taxon>, and the virulence factor P.69 pertactin from <taxon tax_id="520">Bordetella pertussis</taxon> that mediates adhesion to target mammalian cells [<cite idref="PUB00009696"/>].</p>