LcrV

LcrV is a somewhat unstudied part of the Yersinia pestis virulence protein factors that also includes all Yop's, which used to stand for Yersinia outer protein, but now has kept the name out of convention. LcrV's main function is not actually known, but it is essential for the production of other Yops. It is located extracellularly and is related to the lcr (low calcium response) gene in Y. pestis due to only being expressed in the absence of Ca+2 ions. LcrV is excreted, but antibodies produced are protective for this protein, which is not normally associated with regulation proteins in bacteria. The polypeptide is encoded by the plasmid pLCR and is only present when the surroundings are around 37o Celsius.

Source

 * Salyers, Abigail & Whitt, Dixie; Bacterial Pathogenesis: A Molecular Approach, AMS Press
 * Biological Weapons Defense: Infectious Diseases and Counterbioterrorism, Humana Press