A rubrerythrin-like oxidative stress protein of Clostridium acetobutylicum is encoded by a duplicated gene and identical to the heat shock protein Hsp21.
Comparison of the N-terminus of the heat shock protein Hsp21 of Clostridium acetobutylicum with proteins predicted to be encoded by the genome of this bacterium revealed that this stress protein is encoded by two almost identical open reading frames CAC3597 and CAC3598. These genes encode a rubrerythrin-like protein with the rubredoxin-like FeS4 domain at the N-terminus and the ferritin-like diiron domain (rubrerythrin domain) at the C-terminus. Thus, the order of the two putative functional domains is reversed compared to "normal" rubrerythrins. This protein is proposed to be involved in the oxidative stress response of strict anaerobic bacteria. Northern blot analysis indicated that hsp21 is induced by heat and oxidative stress (air, H2O2). Hsp21 of C. acetobutylicum can be considered as a "reverse" rubrerythrin and a role of this stress protein, which is conserved among clostridia and other strict anaerobic bacteria, in the heat and oxidative stress response is proposed.
May
Antje
A
Division of Microbiology, Institute of Biological Sciences, University of Rostock, Albert-Einstein-Str. 3, D-18051 Rostock, Germany.
Hillmann
Falk
F
Riebe
Oliver
O
Fischer
Ralf-Jörg
RJ
Bahl
Hubert
H
D000222:Adaptation, Physiological; D000388:Air; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D015153:Blotting, Western; D003013:Clostridium / Q000235:genetics* / Q000378:metabolism; D005288:Ferredoxins / Q000235:genetics* / Q000502:physiology; D005293:Ferritins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D020131:Genes, Duplicate; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000502:physiology*; D006422:Hemerythrin; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000633:toxicity; D018384:Oxidative Stress; D010100:Oxygen / Q000633:toxicity; D017434:Protein Structure, Tertiary; D020543:Proteome / Q000032:analysis; D012416:Rubredoxins / Q000235:genetics; D017385:Sequence Homology
D001426:Bacterial Proteins; D005288:Ferredoxins; D006360:Heat-Shock Proteins; D006422:Hemerythrin; D020543:Proteome; D012416:Rubredoxins; C055857:rubrerythrins; D005293:Ferritins; D006861:Hydrogen Peroxide; D010100:Oxygen