Metallothionein diversity and distribution in the tree of life: a multifunctional protein.

MTs are small cysteine-rich proteins that chelate metal ions such as Cu+ and Zn2+, and are widely distributed in several life domains, in particular the eukaryotic one. They are present in the following phyla: Opisthokonta (mainly Fungi and Metazoa), Chloroplastida, Alveolata (ciliates) and Excavata (Trichomonas) for Eukaryota and Cyanobacteria, Actinobacteria, Proteobacteria and Firmicutes for Bacteria. However, their absence in some phyla underlines that MTs are far from being fully known.

Metagenomics analysis reveals a new metallothionein family: Sequence and metal-binding features of new environmental cysteine-rich proteins.

Metallothioneins are cysteine-rich proteins, which function as (i) metal carriers in basal cell metabolism and (ii) protective metal chelators in conditions of metal excess. Metallothioneins have been characterized from different eukaryotic model and cultivable species. Presently, they are categorized in 15 families but evolutionary relationships between these metallothionein families remain unresolved.

Construction of sized eukaryotic cDNA libraries using low input of total environmental metatranscriptomic RNA.

Background: Construction of high quality cDNA libraries from the usually low amounts of eukaryotic mRNA extracted from environmental samples is essential in functional metatranscriptomics for the selection of functional, full-length genes encoding proteins of interest. Many of the inserts in libraries constructed by standard methods are represented by truncated cDNAs due to premature stoppage of reverse transcriptase activity and preferential cloning of short cDNAs.

Results: We report here a simple and cost effective technique for preparation of sized eukaryotic cDNA libraries from as low as three microgram of total soil RNA dominated by ribosomal and bacterial RNA.