کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1984272 1539956 2009 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Evolutionary origins and directed evolution of RNA
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Evolutionary origins and directed evolution of RNA
چکیده انگلیسی

In vitro selection experiments show first and foremost that it is possible that functional nucleic acids can arise from random sequence libraries. Indeed, even simple sequence and structural motifs can prove to be robust binding species and catalysts, indicating that it may have been possible to transition from even the earliest self-replicators to a nascent, RNA-catalyzed metabolism. Because of the diversity of aptamers and ribozymes that can be selected, it is possible to construct a ‘fossil record’ of the evolution of the RNA world, with in vitro selected catalysts filling in as doppelgangers for molecules long gone. In this way a plausible pathway from simple oligonucleotide replicators to genomic polymerases can be imagined, as can a pathway from basal ribozyme activities to the ribosome. Most importantly, though, in vitro selection experiments can give a true and quantitative idea of the likelihood that these scenarios could have played out in the RNA world. Simple binding species and catalysts could have evolved into other structures and functions. As replicating sequences grew longer, new, more complex functions or faster catalytic activities could have been accessed. Some activities may have been isolated in sequence space, but others could have been approached along large, interconnected neutral networks. As the number, type, and length of ribozymes increased, RNA genomes would have evolved and eventually there would have been no area in a fitness landscape that would have been inaccessible. Self-replication would have inexorably led to life.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The International Journal of Biochemistry & Cell Biology - Volume 41, Issue 2, February 2009, Pages 254–265
نویسندگان
, , , ,