Cyclodipeptide synthases, a family of class-I aminoacyl-tRNA synthetase-like enzymes involved in non-ribosomal peptide synthesis.

Cyclodipeptide synthases (CDPSs) belong to a newly defined family of enzymes that use aminoacyl-tRNAs (aa-tRNAs) as substrates to synthesize the two peptide bonds of various cyclodipeptides, which are the precursors of many natural products with noteworthy biological activities. Here, we describe the crystal structure of AlbC, a CDPS from Streptomyces noursei. The AlbC structure consists of a monomer containing a Rossmann-fold domain.

Cyclodipeptide synthases are a family of tRNA-dependent peptide bond-forming enzymes.

Cyclodipeptides and their derivatives belong to the diketopiperazine (DKP) family, which is comprised of a broad array of natural products that exhibit useful biological properties. In the few known DKP biosynthetic pathways, nonribosomal peptide synthetases (NRPSs) are involved in the synthesis of cyclodipeptides that constitute the DKP scaffold, except in the albonoursin (1) pathway. Albonoursin, or cyclo(alpha,beta-dehydroPhe-alpha,beta-dehydroLeu), is an antibacterial DKP produced by Streptomyces noursei.

Identification and structural basis of the reaction catalyzed by CYP121, an essential cytochrome P450 in Mycobacterium tuberculosis.

The gene encoding the cytochrome P450 CYP121 is essential for Mycobacterium tuberculosis. However, the CYP121 catalytic activity remains unknown. Here, we show that the cyclodipeptide cyclo(l-Tyr-l-Tyr) (cYY) binds to CYP121, and is efficiently converted into a single major product in a CYP121 activity assay containing spinach ferredoxin and ferredoxin reductase.

Dual expression system suitable for high-throughput fluorescence-based screening and production of soluble proteins.

Many studies that aim to characterize the proteome structurally or functionally require the production of pure protein in a high-throughput format. We have developed a fast and flexible integrated system for cloning, protein expression in Escherichia coli, solubility screening and purification that can be completely automated in a 96-well microplate format. We used recombination cloning in custom-designed vectors including (i) a (His)(6) tag-encoding sequence, (ii) a variable solubilizing partner gene, (iii) the DNA sequence corresponding to the TEV protease cleavage site, (iv) the gene (or DNA fragment) of interest, (v) a suppressible amber stop codon, and (vi) an S.