It is predicted that the psychrophilic metallome of G. antarctica PI12 is zinc-enriched, with the preference of metal uptake decreasing in the order of Zn > Mg > Ca, Fe > Cu, Mn > Na, K, Co, Ni (Table 2). In general, all the results reported by the three approaches mentioned in this study have showed a higher preference for proteins to incorporate transition metal ions (i.e.: manganese, iron, cobalt, nickel, copper and zinc) compared to the alkali (i.e.: sodium and potassium) and alkaline earth metal ions (i.e.: magnesium and calcium). This phenomenon has been explained by Passerini et al. (2006), in which the alkali and alkaline earth metals would tend to bind with proteins through ...view middle of the document...
This has been a great challenge as most of the genomes are seldom been conjugated with the inorganic elements despites for their vital roles .
Previous studies [30-32] had proposed that the metal availability surrounded the habitat of an organism could greatly affected the metal uptake selection and integration into its physiological systems by an organism . The substantial changes in the environment provoked the proteins to evolve with different scaffolds and adopted different metal ions to cope with the stress . Therefore, the effect of chemical changes in the organism and its surrounding environment can be critically influenced its evolution [30, 33].
As noticed in this study, the proteome for thermophilic P. angusta ATCC 26012 is enriched with metals. This observation is concurred to the previous studies conducted by Andreini et al. . They reported that zinc-proteins were prevalent for organisms that thrived in environment with relatively high temperature, especially for the Archaea. The elevated composition of zinc was also detected by Cameron et al.  through experimental elucidation. Presence of zinc was found to be vitally important to retain the stability of the protein structures under such high temperature. Dudev & Lim ( ) believed that the tetrahedrally-bounded zinc was relatively rigid to serve as a structural purpose as it imposed modest hindrance, and therefore was capable in retaining the protein functional conformation .
Intriguingly, we observed a relatively similar fractions of metals composition in G. antarctica PI12 and the baker’s yeast, in which the metal-binding proteins comprised nearly a quarter of the total proteome. The result was conflicting to reported findings by Andreini et al. , as they discovered that the metals content for psychrophiles was lower than mesophiles. The issue regarding the substantially increased of the metals contents in G. antarctica PI12 is urged to be solved, and the association with increased anthropogenic pollutants at the region should also be of concerned. Despite of the differential survival temperature, how these two organisms that are geologically-separated could adopt a similar trend for metal preference is remained to be answered. Nevertheless, Dupont et al.  have proposed that the metals usage in biological systems had actually “leaving a discernible genomics signals” in the genomics puzzles. Hence, a further exploration shall be conducted at omics-level to reveal the possible conserved trend of metal utilization that imprinted in these two organisms by their last common ancestor.
1. Buzzini P, Branda E, Goretti M, Turchetti B: Psychrophilic yeasts from worldwide glacial habitats: diversity, adaptation strategies and biotechnological potential. FEMS microbiology ecology 2012, 82(2):217-241.
2. Feller G: Psychrophilic enzymes: from folding to function and biotechnology. Scientifica 2013, 2013.
3. Bowman JP, Abell GC, Mancuso...