| Armen Mulkidjanian | at 11:00 |
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Affiliation: School of Physics, Universität Osnabrück, D-49069 Osnabrück, Germany, and A.N.Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119991, Russia
Host: Michael Galperin
To what extent did the primeval Zinc World shaped the modern life forms?
According to the “Zn world” scenario of the origin of life, the honeycomb-like structures made of hydrothermally precipitated zinc sulfide (ZnS) may have served as cradles of life [1]. The minute, semiconducting particles of ZnS (so called “quantum dots”), owing to their ability to capture and store the energy of light, are capable of driving high-yield photosynthesis of diverse organic compounds from CO2. Under the high pressure of primordial CO2-dominated atmosphere, the hot, Zn-rich hydrothermal fluids may have discharged to the surface of first continents, so that ZnS nanoparticles precipitated within reach of solar radiation. The porous aggregates of ZnS particles could catalyze various photosynthetic reactions, support the (photo)selection of the first RNA-like polymers and protect them from photodestruction. The photosynthesizing and habitable areas of porous ZnS precipitates around primeval hot springs may have served as the first Earth biotopes.
The ZnS-mediated photosynthesis proceeds with the release of Zn2+ ions. This trait enabled the validation of the Zn world scenario by comparative analysis of the data on the transition metal content in modern cellular systems, including the “evolutionary old” RNA and protein structures [2]. The abundance of Zn in the ubiquitous cellular systems, which were supposedly present in the Last Universal Common Ancestor, indicates that life must have originated and developed in Zn rich environments. Based on this analysis, the traits of modern organisms that stem from the Zn world could be identified.
1. Mulkidjanian AY: On the origin of life in the Zinc World: 1. Photosynthetic porous edifices built of hydrothermally precipitated zinc sulfide (ZnS) as cradles of life on Earth. Biol Direct 2009, 4:26, http://www.biology-direct.com//content/4/1/26
2. Mulkidjanian AY, Galperin MY: On the origin of life in the Zinc World. 2. Validation of the hypothesis on the photosynthesizing zinc sulfide edifices as cradles of life on Earth Biology Direct 2009, 4:27, http://www.biology-direct.com/content/4/1/27
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