L-type lectin domain L-type lectin domain In molecular biology the L-like lectin domain is a protein domain found in lectins which are similar to the leguminous plant lectins. Lectins are structurally diverse proteins that bind to specific carbohydrates. This family includes the VIP36 and ERGIC-53 lectins. Although proteins containging this domain were originally identified as a family of animal lectins, there are also yeast representatives. ERGIC-53 is a 53kDa protein, localised to the intermediate region between the endoplasmic reticulum and the Golgi apparatus (ER-Golgi-Intermediate Compartment, ERGIC). It was identified as a calcium-dependent, mannose-specific lectin. Its dysfunction has been associated with combined factors V
Lectin MBL, the mannose-binding lectin, help mediate the first-line defense against invading microorganisms. Other lectins within the immune system are thought to play a role in self-nonself discrimination and they likely modulate inflammatory and autoreactive processes. Intelectins (X-type lectins) were shown to bind microbial glycans and may function in the innate immune system as well. Lectins may be involved in pattern recognition and pathogen elimination in the innate immunity of vertebrates including fishes. The function of lectins in plants (legume lectin) is still uncertain. Once thought to be necessary for rhizobia binding, this proposed function was ruled out through lectin-knockout transgene