The Outer Membrane Beta-barrel Endoprotease, Omptin (Omptin) Family

The Omptin family is a large family of outer membrane proteases/adhesins, found and studied primarily in enterobacteria (Kukkonen and Korhonen 2004). They play important roes in the degredation of denatured periplasmic proteins (*E. coli*), and funtion in pathogenesis (in *Shigella, Escherichia*, *Yersinia* and *Salmonella*). In *Yersinia pestis*, the Pla protein is a plasminogen activator. It both activates plasminogen and inactivating α2-antiplasmin (Suomalainen *et al.* 2007). It also degrades complement components. In *E. coli*, omptins, OmpT and OmpP, have been shown to cleave and inactivate cationic antimicrobial peptides (Kukkonen and Korhonen 2004). OmpT of *E. coli* cleaves peptide bonds between two basic amino acids using a histidyl residue and an aspartyl residue at the active site of the protease and surprisingly, is functional in high concentrations of urea (Stathopoulos 1998; Hritonenko and Stathopoulos 2007).

The omptins Pla (*Yersinia*) and PgtE (*Salmonella*) attack innate immunity by affecting the
plasminogen/plasmin, complement, coagulation, fibrinolysis, and matrix
metalloproteinase systems, by inactivating antimicrobial peptides, and
by enhancing bacterial adhesiveness and invasiveness (Haiko *et al.* 2009; Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Hritonenko and Stathopoulos 2007).

The omptins enhance pathogenicity and attack innate immunity bynumerous mechanisms: by affecting the
plasminogen/plasmin, complement, coagulation, fibrinolysis, and matrix
metalloproteinase systems, by inactivating antimicrobial peptides, and
by enhancing bacterial adhesiveness and invasiveness (Haiko *et al.* 2009; Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Hritonenko and Stathopoulos 2007).

The omptins enhance pathogenicity and attack innate immunity bynumerous mechanisms: by affecting the
plasminogen/plasmin, complement, coagulation, fibrinolysis, and matrix
metalloproteinase systems, by inactivating antimicrobial peptides, and
by enhancing bacterial adhesiveness and invasiveness (Haiko *et al.* 2009; Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013Korhonen *et al.* 2013Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Hritonenko and Stathopoulos 2007).

The omptins enhance pathogenicity and attack innate immunity bynumerous mechanisms: by affecting the
plasminogen/plasmin, complement, coagulation, fibrinolysis, and matrix
metalloproteinase systems, by inactivating antimicrobial peptides, and
by enhancing bacterial adhesiveness and invasiveness (Haiko *et al.* 2009; Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013Korhonen *et al.* 2013<Hritonenko and Stathopoulos 2007).

The omptins enhance pathogenicity and attack innate immunity bynumerous mechanisms: by affecting the
plasminogen/plasmin, complement, coagulation, fibrinolysis, and matrix
metalloproteinase systems, by inactivating antimicrobial peptides, and
by enhancing bacterial adhesiveness and invasiveness (Haiko *et al.* 2009; Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013Korhonen *et al.* 2013Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Yun and Morrissey 2009; Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013Korhonen *et al.* 2013<Korhonen *et al.* 2013). Although the
mechanistic details of the functions of Pla and PgtE differ, the outcome
is the same: enhanced spread and multiplication of *Y. pestis* and *S.
enterica* in the host. Maximal activity requires association with lipopolysaccharide (Korhonen *et al.* 2013Korhonen *et al.* 2013Korhonen *et al.* 2013Korhonen *et al.* 2013Korhonen *et al.* 2013).

#### References associated with 9.B.50 family:

*Enterobacteriaceae*. Mol. Membr. Biol. 24: 395-406. 17710644

*Yersinia pestis*. Front Cell Infect Microbiol 3: 35. 23898467

*Escherichia coli*to systemic spread of

*Yersinia pestis*. Int. J. Med. Microbiol. 294: 7-14. 15293449

*Yersinia pestis*. Adv Exp Med Biol 603: 268-278. 17966423