Nucleic acids are fundamentally informational macromolecules; their sequence is the cell's genetic operating system and software. The repository of this information lies in DNA that must be copied with unprecedented accuracy precisely once every cell cycle. DNA is repeatedly read out (transcribed) before sending its information out to where it becomes used to program the synthesis of proteins. The integrity of the genetic blueprint is vital to the cell, and yet the structure of DNA is under constant onslaught. Thus precise mechanisms exist to repair damage in DNA; it is the only cellular molecule for which this occurs to a significant extent. DNA undergoes recombination, a kind of molecular cut and join that creates diversity to facilitate evolution, yet also provides an important method of repair. In eukaryotic cells DNA is packaged into chromosomes in a way that allows something like 2 m of nucleic acid to be packed into the cell nucleus, yet remain accessible to the cellular machinery that reads out its genetic information.
By contrast RNA is highly dynamic. It is the worker bee of genetics to the DNA's queen, and an extremely versatile molecule. In the central dogma it is the messenger (mRNA) that passes the information between the DNA library and the protein synthesis factory, yet it does much, much more. In translation of the genetic information it is the key component of the ribosome, as well as the tRNA species that activate and deliver the amino acids and decode the message. In eukaryotic cells the pre-mRNA must be processed by the precise removal of intervening sequences (introns), carried out by a large and dynamic RNA-protein machine called the spliceosome. Failure to do this correctly can lead to disease, and it is now becoming possible to create therapies that correct this. Increasingly we realize that RNA is also involved in critical and complex regulatory processes. RNA can act as a molecular switch responding to small molecules in order to control gene expression. Indeed while most of the information in DNA is not protein coding, almost all of it is transcribed into RNA. We are only just beginning the long journey of understanding what all this non-coding RNA is doing - it is very much the 'dark matter' of biology! Lastly RNA can also accelerate chemical reactions by a million fold or more in the manner of an enzyme. This is very likely of key significance in the origin of life on the planet more than three billion years ago.
Understanding processes involving DNA and RNA at the molecular and chemical level is the central theme of this conference, with a marked structural and mechanistic perspective. Every two years we have a hot topic theme and have previously covered ribosome, spliceosome, exosome, ncRNA regulation, DNA replication initiation, DNA topology and repair at past meetings. In 2022, our hot topic will likely be RNA viruses.