1.C.109 The Bacterial Hemolysin A (TlyA) Family

The hemolysins (TlyA proteins) of Serpulina (Brachyspira) hyodysenteriae are active at 27 to 40 degrees C and pH 3 to 9 and are unaffected by enzymatic inhibitors. Pore formation was demonstrated by the inhibition of hemolysis with molecules of 2.0 to 2.3 nm in diameter and the release of 86Rb  from erythrocytes without hemoglobin release after exposure to native hemolysin (Hyatt and Joens 1997). TlyA sequences and their conserved domains in mycobacterial proteins revealed the basis for their pore-forming activities and further confirmed their roles as virulence proteins (Sharma and Singh 2022).



Arenas, N.E., L.M. Salazar, C.Y. Soto, C. Vizcaíno, M.E. Patarroyo, M.A. Patarroyo, and A. Gómez. (2011). Molecular modeling and in silico characterization of Mycobacterium tuberculosis TlyA: possible misannotation of this tubercle bacilli-hemolysin. BMC Struct Biol 11: 16.

Hyatt, D.R. and L.A. Joens. (1997). Analysis of the lytic activity of the Serpulina hyodysenteriae hemolysin. Infect. Immun. 65: 4877-4879.

Javadi, M.B. and G. Katzenmeier. (2016). The Forgotten Virulence Factor: The ''non-conventional'' Hemolysin TlyA And Its Role in Helicobacter pylori Infection. Curr. Microbiol. 73: 930-937.

Lata, K. and K. Chattopadhyay. (2014). Helicobacter pylori TlyA agglutinates liposomes and induces fusion and permeabilization of the liposome membranes. Biochemistry 53: 3553-3563.

Monshupanee, T. (2013). Increased bacterial hemolytic activity is conferred by expression of TlyA methyltransferase but not by its 2'-O-methylation of the ribosome. Curr. Microbiol. 67: 61-68.

Rahman, A., S.S. Srivastava, A. Sneh, N. Ahmed, and M.V. Krishnasastry. (2010). Molecular characterization of tlyA gene product, Rv1694 of Mycobacterium tuberculosis: a non-conventional hemolysin and a ribosomal RNA methyl transferase. BMC Biochem 11: 35.

Rajesh, T., J.M. Jeon, Y.H. Kim, H.J. Kim, d.a.H. Yi, S.H. Park, K.Y. Choi, Y.G. Kim, J. Kim, S. Jung, H.Y. Park, and Y.H. Yang. (2013). Functional analysis of the gene SCO1782 encoding Streptomyces hemolysin (S-hemolysin) in Streptomyces coelicolor M145. Toxicon 71: 159-165.

Ramarao, N. and V. Sanchis. (2013). The pore-forming haemolysins of bacillus cereus: a review. Toxins (Basel) 5: 1119-1139.

Sałamaszyńska-Guz, A. and D. Klimuszko. (2008). Functional analysis of the Campylobacter jejuni cj0183 and cj0588 genes. Curr. Microbiol. 56: 592-596.

Sharma, M. and P. Singh. (2022). Role of TlyA in the Biology of Uncultivable Mycobacteria. Comb Chem High Throughput Screen. [Epub: Ahead of Print]

Ulens, C. (2018). Structure of a transporter domain emerges. J. Biol. Chem. 293: 20008-20009.


TC#NameOrganismal TypeExample

Hemolysin A, TlyA of 240 aas


TlyA of Brachyspira (Serpulina) hyodysenteriae


S-Hemolysin of 271 aas (Rajesh et al. 2013).


S-Hemolysin of Streptomyces coelicolor


Putative hemolysin of 253 aas, TlyA.  In one study hemolysin activity was not detected, but adhsion to Caco cells was demonstrated (Sałamaszyńska-Guz and Klimuszko 2008).


TlyA of Campylobacter jejuni


Hemolysin and RNA methyltransferase of 268 aas, TlyA (Rahman et al. 2010; Monshupanee 2013).  The assignment of this protein as an hemolysin has be questioned (Arenas et al. 2011).


TlyA of Mycobacterium tuberculosis


Haemolysin III, TlyA family member of 279 aas (Ramarao and Sanchis 2013).


Haemolysin of Bacillus cereus


The 'non-conventional' hemolysin, TlyA, a pore-forming hemolysin with potent cytotoxic activity, is of 235 aas (Javadi and Katzenmeier 2016).  It causes agglutination, fusion and permeability of synthetic liposome vesicles. Agglutination activity could also be observed with erythrocytes before the induction of its pore-forming hemolytic activity. TlyA also induces disruption of liposome membranes (Lata and Chattopadhyay 2014).


TlyA of Helicobacter pylori