Role of HdeA in acid resistance and virulence in Brucella abortus 2308

HdeB Functions as an Acid-protective Chaperone in Bacteria

“…The two genes coding for HdeA and HdeB are part of a larger hdeA-hdeB acid stress operon and are induced upon exposure of cells to low pH (12). Their deletion is reported to negatively affect the growth and survival of several enteric bacteria under low pH conditions (10,11,13,14). HdeA and HdeB share 13% sequence identity at the amino acid level, and their structures can be aligned with root mean square deviation of 1.75 Å (15).…”

The cyanobacterial homologue of the RNA chaperone Hfq is essential for motility of Synechocystis sp. PCC 6803

“…In this context, there are several reports on Hfq-mediated adaptation to changing environmental conditions, exemplified by Brucella abortus (Robertson & Roop, 1999;Gee et al, 2005;Valderas et al, 2005), Salmonella typhimurium and Azorhizobium caulinodans, as well as the phototrophs Rhodobacter capsulatus (Kaminski et al, 1994;Kaminski & Elmerich, 1998;Drepper et al, 2002) and Rhodobacter sphaeroides (Glaeser et al, 2007). In contrast, no apparent phenotype emerged from an hfq knockout in Staphylococcus aureus (Bohn et al, 2007).…”

Comparative proteomics reveal distinct chaperone–client interactions in supporting bacterial acid resistance

“…Noteworthy, the HdeA and HdeB genes are regulated by a single promoter (7) and are well-conserved in various serotypes and pathotypes of E. coli, Shigella flexneri, and Brucella abortus (2). This hdeAB operon is highly expressed in response to acid stress (8), whereas disruption of these genes renders such bacteria extremely vulnerable to acid (5,9,10). Determining how these two acid chaperones cooperate to protect a broad range of periplasmic client proteins from acid denaturation during bacterial passage through the human stomach is central to understanding their acid-resistance mechanism.…”