Abstract:
:Chlamydia trachomatis R2c is the prototype for a recently discovered group of ribonucleotide reductase R2 proteins that use a heterodinuclear Mn/Fe redox cofactor for radical generation and storage. Here, we show that the Mycobacterium tuberculosis protein Rv0233, an R2 homologue and a potential virulence factor, contains the heterodinuclear manganese/iron-carboxylate cofactor but displays a drastic remodeling of the R2 protein scaffold into a ligand-binding oxidase. The first structural characterization of the heterodinuclear cofactor shows that the site is highly specific for manganese and iron in their respective positions despite a symmetric arrangement of coordinating residues. In this protein scaffold, the Mn/Fe cofactor supports potent 2-electron oxidations as revealed by an unprecedented tyrosine-valine crosslink in the active site. This wolf in sheep's clothing defines a distinct functional group among R2 homologues and may represent a structural and functional counterpart of the evolutionary ancestor of R2s and bacterial multicomponent monooxygenases.
journal_name
Proc Natl Acad Sci U S Aauthors
Andersson CS,Högbom Mdoi
10.1073/pnas.0812971106subject
Has Abstractpub_date
2009-04-07 00:00:00pages
5633-8issue
14eissn
0027-8424issn
1091-6490pii
0812971106journal_volume
106pub_type
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