Protein sequences bound to mineral surfaces persist into deep time
Protein sequences bound to mineral surfaces persist into deep time
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DOI：
10.7554/elife.17092
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发表时间：
2016-09-27
期刊：
影响因子：
7.7
通讯作者：
Collins, Matthew J.
中科院分区：
文献类型：
--
作者：
Demarchi, Beatrice;Hall, Shaun;Collins, Matthew J.
蛋白质在化石记录中的存在时间比DNA长，但寿命，生存机制和底物仍然存在争议。在这里，我们展示了矿物结合在保存鸵鸟（Struthionidae）蛋壳中的蛋白质序列中的作用，包括来自坦桑尼亚Laetoli（3.8 Ma）和Olduvai Gorge（1.3 Ma）的古生物学遗址。通过及时追踪蛋白质成岩作用，我们发现了一致的保存模式，证明了幸存序列的真实性。struthiocalcin-1和-2，蛋壳内的优势蛋白质的分子动力学模拟，揭示了不同的域绑定到矿物表面。它是具有最强的计算结合能的域的方解石表面被选择性地保存。热年龄计算表明，Laetoli和Olduvai肽比任何先前鉴定的序列都要古老50倍（相当于在恒定10摄氏度下的16 Ma）。
Proteins persist longer in the fossil record than DNA, but the longevity, survival mechanisms and substrates remain contested. Here, we demonstrate the role of mineral binding in preserving the protein sequence in ostrich (Struthionidae) eggshell, including from thepalaeontological sites of Laetoli (3.8 Ma) and Olduvai Gorge (1.3 Ma) in Tanzania. By tracking protein diagenesis back in time we find consistent patterns of preservation, demonstrating authenticity of the surviving sequences. Molecular dynamics simulations of struthiocalcin-1 and -2, the dominant proteins within the eggshell, reveal that distinct domains bind to the mineral surface. It is the domain with the strongest calculated binding energy to the calcite surface that is selectively preserved. Thermal age calculations demonstrate that the Laetoli and Olduvai peptides are 50 times older than any previously authenticated sequence (equivalent to similar to 16 Ma at a constant 10 degrees C).