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1.C.11.1.1
Leukotoxin, HlaA or LktA of 955 aas and 2 TMSs. Cytolysin LktA is one of the major pathogenicity factors of Mannheimia haemolytica (formerly Pasteurella haemolytica) that is the cause of pasteurellosis, also known as shipping fever pneumonia, causing substantial loss of sheep and cattle during transport. LktA belongs to the family of RTX-toxins (Repeats in ToXins) that are produced as pathogenicity factors by a variety of Gram-negative bacteria. Sublytic concentrations of LktA cause inflammatory responses of ovine leukocytes while higher concentrations result in formation of transmembrane channels in target cells that may cause cell lysis and apoptosis. Channel formation by LktA occurs in artificial lipid bilayer membranes made of different lipids. LktA channels had a single-channel conductance of about 60 pS in 0.1 M KCl, which is about one tenth of the conductance of most RTX-toxins with the exception of the adenylate cyclase toxin of Bordetella pertussis (Benz et al. 2019). The LktA channels are highly cation-selective, and the channel diameter is around 1.5 nm.

Accession Number:P55117
Protein Name:LKAA aka HlaA aka LKTA
Length:955
Molecular Weight:102128.00
Species:Pasteurella haemolytica [47735]
Number of TMSs:2
Location1 / Topology2 / Orientation3: Secreted1 / Multi-pass membrane protein2
Substrate molecule

Cross database links:

Pfam: PF00353    PF02382    PF08339   

Gene Ontology

GO:0020002 C:host cell plasma membrane
GO:0016021 C:integral to membrane
GO:0005509 F:calcium ion binding
GO:0019835 P:cytolysis
GO:0019836 P:hemolysis by symbiont of host erythrocytes
GO:0009405 P:pathogenesis

References (3)

[1] “Molecular analysis of the leukotoxin determinants from Pasteurella haemolytica serotypes 1 to 16.”  Burrows L.L.et.al.   8225575
[2] “Characterization of epitopes involved in the neutralization of Pasteurella haemolytica serotype A1 leukotoxin.”  Lainson F.A.et.al.   8828217
[3] “Sequence diversity and molecular evolution of the leukotoxin (lktA) gene in bovine and ovine strains of Mannheimia (Pasteurella) haemolytica.”  Davies R.L.et.al.   11157953

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Predict TMSs (Predict number of transmembrane segments)
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FASTA formatted sequence 
1:	MGTKLTLSTL SNGIRSTLTA TRGGLNRAGQ SLTQAGQTLK NGAKKIILYI PKDYKYDSGS 
61:	GNGLQDLVKA AEELGIEVQK EEGNDIAKAQ TSLGTIQNVL GLTERGIVLS APQLDKLLQK 
121:	NKVGQALGSS ESIAQNFSQA KTVLSGVQSI LGSVLAGMDL DEALQNESDQ LTLAKAGLEL 
181:	TNSLIENIAN SVQTLDAFSE QISQFGSKLQ NVKGLGALGD KLKNIGGLDK AGLGLDVISG 
241:	LLSGATAALV LADKDASTAK KVGAGFELAN QVVGNITKAV SSYILAQRVA AGLSSTGPVA 
301:	ALIASTVALA ISPLSFAGIA DKFDRAKSLE NYAERFKKLG YEGDSLLAEY QHGTGTIDAS 
361:	VTAINTALAA IAGGVSAAAA GSVVASPIAL LVSGITGVIS TILQYSKQAM FEHVANKIHN 
421:	KIVEWEKNNG GKNYFENGYD ARYLANLQDN MKFLLNLNKE LQAERVIAIT QQQWDSNIGD 
481:	LAGISRLGEK VLSGKAYVDA FEEGQHLKAD KLVQLDSAKG IIDVSNTGEA KTQHILFRTP 
541:	LLTPGTEKRE RVQTGKYEYI TKLHINRVDS WQIKDGAASS TFDLTNVVQR IGVELDHAEN 
601:	VIKTKETKIV ATLGDGDDNV FVGSGTTEID GGEGYDRVHY SRGNYGALTI DATKETEQGS 
661:	YTVNRFVESG KALHEVTSTH TALVGNREEK IEYRHSNNQH HAGYYTKDTL KAVEEIIGTS 
721:	HNDIFKGSKF NDAFNGGDGV DTIDGNDGND RLFGGKGDDI IDGGNGDDFI DGGKGNDLLH 
781:	GGKGDDIFVH RQGDGNDSIT ESEGNDKLSF SDSNLKDLTF EKVNHHLVIT NTKQEKVTIQ 
841:	NWFREAEFAK TIRNYVATRD DKIEEIIGQN GERITSKQVD ELIEKGKGKI DKSDLSQVVD 
901:	NYQLLKYSRD ASNSLDKLIS SASAFTSSND SRNVLASPTS MLDPSLSSIQ FARAA