This entry represents the Adhesion domain found in InvasinE (invE). Invasins are members of the inverse autotransporter (IAT) family also referred to as type Ve secretion system. In general, they consist of an N-terminal beta-barrel-like domain, which is responsible for attachment of invasin to the outer membrane region of bacteria, repetitive Immunoglobulin-like (Ig) domains, which vary significantly in number among all the invasins, and the C-terminal domain/adhesion domain (AD), which provides invasins with the specificity to bind to its host target molecules. InvE-AD adopts a C-type lectin-like domain (CTLD)fold with unique modifications. The core structure of the adhesion domain (AD) is made up of a globular alpha/beta fold and can be divided into three sub-sections. The first is a lasso-shaped loop structure termed the "adaptor ring" since it forms a ring-shaped platform that connects BIg21 Pfam:PF05688 with the two residual sub-sections in the AD. These two residual subsections are the "C-type lectin-like domain" and the "wedge module". InvE-CTLD lacks the ability to coordinate Ca2+, and motifs such as EPN, QPD, and WND that are responsible for the specificity of carbohydrate recognition are also absent, giving rise to the notion that the InvE-CTLD is not a carbohydrate binding domain [1].

1: Structure of the Y. pseudotuberculosis adhesin InvasinE. Sadana P, Monnich M, Unverzagt C, Scrima A; Protein Sci. 2017;26:1182-1195. PMID:28370712