Neorickettsia risticii surface-exposed proteins: proteomics identification, recognition by naturally-infected horses, and strain variations

Table 3 Proteomics-identified proteins for two N.risticii strains.

Locus ID	Protein name	Mol Mass (kDa)	pI^a	% (query) peptide coverage^b	Signal peptide^c
*N. risticii* Illinois ^T
NRI_0235	51-kDa antigen (P51)	54.9	8.44	49.2 (139)	Yes (20-21)
NRI_0614	Heat shock protein 60 (GroEL)	58.1	5.23	43.2 (36)	No
NRI_0841	Neorickettsia surface protein 3 (Nsp3)	25.7	5.96	12.0 (2)	Yes (24-25)
NRI_0567	Conserved hypothetical protein	50.9	4.26	9.85 (2)	No
PA-1
NRI_0235	P51	54.9	8.44	34.6 (41)	Yes (20-21)
NRI_0614	GroEL	58.1	5.23	45.6 (36)	No
NRI_0017	Heat shock protein 70 (DnaK)	68.4	5.18	2.20 (6)	No
NRI_0132	ATP synthase F1, alpha subunit (AtpA)	55.9	5.29	2.75 (3)	No
NRI_0872	Strain-specific surface antigen 3 (Ssa3)	41.9	6.01	2.36 or 4.72^d (2)	No

^aTheoretical isoelectric point of the given protein as predicted by ExPASy Compute pI/MW tool [64].
^bIndicates percentage coverage of proteins by all peptides. Numbers in parentheses are the number of peptide queries for each protein identified in the given band.
^cSignal peptide presence as determined by the Center for Biological Sequence Analysis SignalP v.3.0 [65]. Parentheses indicate amino acids between which cleavage is predicted to occur in the given protein.
^dThe peptide detected twice was within the repeated region of Ssa3, therefore the percentage coverage could be two different percentages.

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