Editors' ChoiceBiochemistry

Simply Mycoplasma

See allHide authors and affiliations

Science Signaling  01 Dec 2009:
Vol. 2, Issue 99, pp. ec386
DOI: 10.1126/scisignal.299ec386

The bacterium Mycoplasma pneumoniae, a human pathogen, has a genome of reduced size and is one of the simplest organisms that can reproduce outside of host cells. As such, it may be an excellent model organism in which to attempt a systems-level understanding of its biological organization. Now three papers provide a comprehensive and quantitative analysis of the proteome, the metabolic network, and the transcriptome of M. pneumoniae (see the Perspective by Ochman and Raghavan). Anticipating what might be possible in the future for more complex organisms, Kühner et al. combine analysis of protein interactions by mass spectrometry with extensive structural information on M. pneumoniae proteins to reveal how proteins work together as molecular machines and even map their organization within the cell by electron tomography. The manageable genome size of M. pneumoniae allowed Yus et al. to manually map the metabolic network of the organism and validate it experimentally. Analysis of the network aided development of a minimal medium in which the bacterium could be cultured. Fundamental insights from the studies are derived from evidence that growth rate or generation of biomass is not maximized and from demonstration that complex regulatory responses are maintained despite the reduced genome, partly by use of multifunctional enzymes and possibly by previously unrecognized posttranscriptional regulation. Finally, Güell et al. applied state-of-the-art sequencing techniques to reveal that this “simple” organism makes extensive use of noncoding RNAs and has an exon-intron-like structure within transcriptional operons that allows complex gene regulation resembling that of eukaryotes.

S. Kühner, V. van Noort, M. J. Betts, A. Leo-Macias, C. Batisse, M. Rode, T. Yamada, T. Maier, S. Bader, P. Beltran-Alvarez, D. Castaño-Diez, W.-H. Chen, D. Devos, M. Güell, T. Norambuena, I. Racke, V. Rybin, A. Schmidt, E. Yus, R. Aebersold, R. Herrmann, B. Böttcher, A. S. Frangakis, R. B. Russell, L. Serrano, P. Bork, A.-C. Gavin, Proteome organization in a genome-reduced bacterium. Science 326, 1235–1240 (2009). [Abstract] [Full Text]

E. Yus, T. Maier, K. Michalodimitrakis, V. van Noort, T. Yamada, W.-H. Chen, J. A. H. Wodke, M. Güell, S. Martínez, R. Bourgeois, S. Kühner, E. Raineri, I. Letunic, O. V. Kalinina, M. Rode, R. Herrmann, R. Gutiérrez-Gallego, R. B. Russell, A.-C. Gavin, P. Bork, L. Serrano, Impact of genome reduction on bacterial metabolism and its regulation. Science 326, 1263–1268 (2009). [Abstract] [Full Text]

M. Güell, V. van Noort, E. Yus, W.-H. Chen, J. Leigh-Bell, K. Michalodimitrakis, T. Yamada, M. Arumugam, T. Doerks, S. Kühner, M. Rode, M. Suyama, A.-C. Gavin, P. Bork, L. Serrano, Transcriptome complexity in a genome-reduced bacterium. Science 326, 1268–1271 (2009). [Abstract] [Full Text]

H. Ochman, R. Raghavan, Excavating the functional landscape of bacterial cells. Science 326, 1200–1201 (2009). [Summary] [Full Text]

Stay Connected to Science Signaling