Biosynthesis of Riboflavin: Structure and mechanism of lumazine synthase

Crystallographic Studies on Decameric Brucella spp. Lumazine Synthase: A Novel Quaternary Arrangement Evolved for a New Function?

“…This, along with the inability of certain microorganisms to incorporate exogenous riboflavin, [1][2][3] identify the enzymes involved in riboflavin biosynthesis as promising targets of chemotherapeutic agents. 4 The biosynthesis of riboflavin has been studied extensively. [5][6][7][8][9] Figure 1 highlights the terminal reactions of this process.…”

Plant Riboflavin Biosynthesis

“…Surprisingly, plant LS is a nuclear-encoded protein that is synthesized in the cytosol as a larger precursor with an N-terminal chloroplast targeting sequence. Following import into chloroplasts, the transit peptide is removed to yield "mature" LS, which assembles into a large spherical particle that superficially resembles the icosahedral 60-mers that have been described for E. coli and B. subtilis (5,7). In contrast, fungal LS (the only other eucaryotic LS homologs for which sequence information is available) is synthesized in its mature form without an obvious organellar targeting sequence and upon folding does not assemble into a higher order structure larger than a pentamer (12).…”

“…In Bacillus subtilis, these proteins physically interact with each other to form a huge spherical particle with a combined molecular mass of ϳ1 MDa (2); the x-ray structure of this complex has been determined at 3.3 Å (3). Through an elegant series of experiments, Bacher and co-workers (4,5) have shown that the outer shell of the B. subtilis LS-RS complex consists of 60 LS subunits that are organized as 12 densely packed pentamers to form a hollow icosahedral capsid. Encaged within the central core of the sphere resides a single molecule of RS, a trimer of three identical subunits.…”

Understanding the riboflavin biosynthesis pathway for the development of antimicrobial agents

“…The biosynthesis of riboflavin has been studied extensively in a variety of microorganisms and plants. [18][19][20][21][22][23][24] A structural investigation of the LS-RS complex in Bacillus subtilis revealed that LS is present as an outer icosahedral capsid containing 60β subunits, whereas RS has an inner core with 3α subunits present in the central cavity. 25,26 LS catalyzes the penultimate step in the biosynthesis of riboflavin.…”