sentence: These included orthologs of YPO3720 / YPO3721 , a hemolysin and activator protein in Y. intermedia , Y. bercovieri and Y. fredricksenii ; YPO0599 , a heme utilization protein also found in Y. intermedia ; and YPO0399 , an enhancin metalloprotease that had an ortholog in Y. kristensenii ( ykris0001_41250 ) .