Maria Nikulkova is presenting her work this week on some new Aenigmarchaeota genomes at the American Society for Microbiology annual meeting (ASM Microbe). She also was awarded the ASM Capstone Research Fellowship this year! With this award, Maria gets her travel to present her poster at the ASM Microbe meeting covered, and will participate in the ASM Microbe Academy for Professional Development. Congratulations, Maria!

Complex evolutionary history of translation Elongation Factor 2 and diphthamide biosynthesis in Archaea and parabasalids

This is the product of a great collaboration with some excellent labs and people.

Diphthamide is a modified histidine residue which is uniquely present in archaeal and eukaryotic elongation factor 2 (EF-2), an essential GTPase responsible for catalyzing the coordinated translocation of tRNA and mRNA through the ribosome. In part due to the role of diphthamide in maintaining translational fidelity, it was previously assumed that diphthamide biosynthesis genes (dph) are conserved across all eukaryotes and archaea. Here, comparative analysis of new and existing genomes reveals that some archaea (i.e., members of the Asgard superphylum, Geoarchaea, and Korarchaeota) and eukaryotes (i.e., parabasalids) lack dph. In addition, while EF-2 was thought to exist as a single copy in archaea, many of these dph-lacking archaeal genomes encode a second EF-2 paralog missing key-residues required for diphthamide modification and for normal translocase function, perhaps suggesting functional divergence linked to loss of diphthamide biosynthesis. Interestingly, some Heimdallarchaeota previously suggested to be most closely related to the eukaryotic ancestor maintain dph genes and a single gene encoding canonical EF-2. Our findings reveal that the ability to produce diphthamide, once thought to be a universal feature in archaea and eukaryotes, has been lost multiple times during evolution, and suggest that anticipated compensatory mechanisms evolved independently.

The lab feels like it’s emptying out, with 1 PhD, 1 MS, and 2 BS graduates this May. Congratulations to: Dr. Adrienne Narrowe, PhD (with both the College of Liberal Arts and Sciences and the Department of Integrative Biology outstanding Defense awards) David Banks-Richardson, MS Biology Maria Nikulkova, BS Biology Connor Jacobs, BS Biology

A great accomplishment for each of them, and the whole lab can’t wait to see what each accomplishes next.

Our Old Woman Creek Wetlands team has a new publication out revealing that much of the methane in this wetland appears to come from a novel methanogen residing in surface, oxygenated soils. Congratulations and thanks to the Wrighton and Bohrer labs, who led this work.

Angle, J.C., Morin, T.H., Solden, L.M., Narrowe, A.B., Smith, G.J., Borton, M.A., Rey-Sanchez, C., Daly, R.A., Mirfenderesgi, G., Hoyt, D.W., Riley, W.J., Miller, C.S., Bohrer, G. & Wrighton, K.C., 2017. Methanogenesis in oxygenated soils is a substantial fraction of wetland methane emissions. Nature Communications, 8(1), p.1567.

Congratulations to Mallika, who successfully defended her MS Thesis, “Prediction of Prokaryotic Optimum Growth Temperature Based on Genomic And Proteomic Features.” Mallika did a great job, showing her mastery of her research and the literature.

Mallika is off to the Burnham Institute to pursue her PhD with Adam Godzik.

2017 Integrative Biology Outstanding Graduate Student of the Year: Adrienne Narrowe!

Congratulations, Adrienne.

Congratualtions to Master of Science Kendra DeHay, graduating from the Master’s Program in Biomedical Sciences & Biotechnology!

Congratulations to Mallika and to Nihal! Both are headed to do great things in great PhD programs. Mallika will be joining Adam Godzik’s group at the Sanford Burnham Prebys Medical Discovery Institute, and Nihal is joining the UC Irvine Interdepartmental Neuroscience Program. Each program is lucky to have an exceptional student.

Our publication describing the unexplored archaeal diversity in the Old Woman Creek freshwater wetland has been accepted to Environmental Microbiology.

High-resolution sequencing reveals unexplored archaeal diversity in freshwater wetland soils

This research, which was led by Adrienne, results from work done with our great collaborators in the Wrighton Lab.