5esc

Crystal structure of Group A Streptococcus HupZCrystal structure of Group A Streptococcus HupZ

Structural highlights 5esc is a 4 chain structure with sequence from Streptococcus sp. 'group A'. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q1JHG0_STRPD Publication Abstract from PubMed In Group A streptococcus (GAS), the metallorepressor MtsR regulates iron homeostasis. Here we describe a new MtsR-repressed gene, which we named hupZ (heme utilization protein). A recombinant HupZ protein was purified bound to heme from Escherichia coli grown in the presence of 5-aminolevulinic acid and iron. HupZ specifically binds heme with stoichiometry of 1:1. The addition of NADPH to heme-bound HupZ (in the presence of cytochrome P450 reductase, NADPH-regeneration system and catalase) triggered progressive decrease of the HupZ Soret band and the appearance of an absorption peak at 660 nm that was resistance to hydrolytic conditions. No spectral changes were observed when ferredoxin and ferredoxin reductase were used as redox partners. Differential spectroscopy with myoglobin or with the ferrous chelator, ferrozine, confirmed that carbon monoxide and free iron are produced during the reaction. ApoHupZ was crystallized as a homodimer with a split beta-barrel conformation in each monomer comprising six beta strands and three alpha helices. This structure resembles the split beta-barrel domain shared by the members of a recently described family of heme degrading enzymes. However, HupZ is smaller and lacks key residues found in the proteins of the latter group. Phylogenetic analysis places HupZ on a clade separated from those for previously described heme oxygenases. In summary, we have identified a new GAS enzyme-containing split beta-barrel and capable of heme biotransformation in vitro; to the best of our knowledge, this is the first enzyme among Streptococcus species with such activity. In vitro heme biotransformation by the HupZ enzyme from Group A streptococcus.,Sachla AJ, Ouattara M, Romero E, Agniswamy J, Weber IT, Gadda G, Eichenbaum Z Biometals. 2016 May 6. PMID:27154580 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 5esc, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image