Putting the pieces together

Oeiras, 09.09.10

By uncovering the function of a new bacterial membrane protein complex researchers from the Bacterial Energy Metabolism Laboratory at ITQB have brought in a key piece to the puzzle of understanding the bioenergetic pathways of an important group of anaerobic bacteria. The findings are now published in the Journal of Biological Chemistry.

The sequencing of an ever growing number of microbial genomes has greatly improved our understanding of their biological mechanisms. However, it also unraveled how much we have left to understand, since 30 to 40% of sequenced genes have no attributed function. Even when individual genes are identified, it is often not clear what the actual function of a multisubunit complex protein might be, just from its gene analysis.

A striking example is provided by the new respiratory complex, Qrc. Although Qrc has a gene composition similar to other bacterial complexes, biochemical studies showed that it actually performs a completely different function, which could not have been predicted based only on gene sequence analysis. This discovery makes a significant contribution to understanding energy metabolism in sulfate-reducing bacteria, an important group of organisms for bioremediation and bioenergy production processes.

Original Article

The Journal of Biological Chemistry, 285, 22774-22783

The Qrc Membrane Complex, Related to the Alternative Complex III, Is a Menaquinone Reductase Involved in Sulfate Respiration

Sofia S. Venceslau, Rita R. Lino and Inês A. C. Pereira