Genetic organisation of the htrA locus and HtrA expression in worldwide H
. pylori strains.
A. Schematic representation of the htrA gene locus in H
. pylori strain 26695 (Tomb et al., 1997). Shown is the organisation of genes designated HP1017 to HP1022. In the original publication, the htrA gene is separated into two genes, called HP1018 and HP1019 (Tomb et al., 1997). The proposed start of gene HP1018 is at position 1,081,440 and HP1019 at position 1,081,537 in the 26695 genome.
B. Re‐sequencing of the htrA gene locus in the same strain (G1JZF0 – G1JZF0_HELPY) has then shown that htrA is a single gene of 1,428 bp length due to a missing guanidine residue at position 1,081,558 which resulted in a frameshift and two putative genes (Löwer et al., 2008).
C. Analysis of fully sequenced H
. pylori isolates from all continents showed that the full‐length htrA gene is 1,428 bp long.
D. Western blots of the HtrA proteins in these strains as well as recombinant HtrA (rHtrA) revealed bands of 52 kDa (p52) and 55 kDa (p55) as indicated by arrows. Loading control blots for CagA and urease B are shown. One of the strains, Safr7, is cag
PAI‐negative and therefore lacks CagA.