This family consists of several bacteria specific low temperature requirement A (LtrA) protein sequences which have been found to be essential for growth at low temperatures in Listeria monocytogenes [1].

1: Differentiation of epidemic-associated strains of Listeria monocytogenes by restriction fragment length polymorphism in a gene region essential for growth at low temperatures (4 degrees C). Zheng W, Kathariou S; Appl Environ Microbiol 1995;61:4310-4314. PMID:8534098