Ribozymes are catalytic molecules that cleave the ribonucleic acid (RNA) at specific sequences (Gesteland et al. 2006). RNA is the nucleic acid that is made in the process of transcription; when the deoxyribonucleic acid (DNA) anneals, it transcribes itself into a linear stranded molecule called RNA. In order for RNA to synthesise proteins, it requires catalytic enzymes to perform certain chemical reactions. In the past, it was thought that all chemical reactions are catalysed by protein enzymes; however, in the eighties this hypothesis was disproved as Thomas Cech and Sydney Altman discovered that RNA is able to carry out self-catalysing activities which were named as ribozymes because they perform similar functions as the protein enzymes (Jaeger, 1997). Even though, RNA ribozymes lack the functional groups diversity found in protein enzymes, they are able to carry out their own catalytic reactions due to their tendency to fold into a 3D structure and form helices by Watson-Crick base pairing role (Kiehntopf et al. 1995). Ribozymes are now play critical role in the understanding of biochemistry, as they have the ability to catalyse some of the most important chemical reactions such as RNA splicing as well as the synthesis of peptides, for instance ribozymes can speed up the phosphoryl transfer chemical reactions by 1011 folds. This review will describe the structure, sources and applications of ribozymes.
There are several naturally occurring ribozymes that have been identified to date; these are divided into three distinct classes. Firstly, the self splicing introns that fall into groups I and II respectively depending on their structure and the recognition sequences. Self splicing group I intron was the first ribozyme to b...
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...the cells, the localisation of the ribozymes in the cells as well as the selection site of the messengerRNA (James and Gibson, 1998).
Ribozymes are currently considered to hold many promises for the future development of gene therapy as they have the ability to splice and cleave any target RNA sequences. There are seven natural ribozymes known and several artificial ribozymes have been created. These artificial ribozymes are being used as therapeutic agent to target the aberrant gene expression in many lethal diseases such as cancer. The limitation of artificial ribozymes is mainly due to the difficulty in their delivery to the target cells. Therefore, more research needs to be conducted in thoroughly studying the organisation and structures of the natural RNA ribozymes to achieve successful artificial ribozymes that have complex function in the future.
Miller, Kenneth R. and Joseph S. Levine. “Chapter 12: DNA and RNA.” Biology. Upper Saddle River: Pearson Education, Inc., 2002. Print.
The study of nucleic acids has now become a fruitful and dynamic scientific enterprise. Nucleic acids are of unique importance in biological systems. Genes are made up of deoxyribonucleic acid or DNA, and each gene is a linear segment, or polymer, of a long DNA molecule. A DNA polymer, or DNA oligonucleotide, contains a linear arrangement of subunits called nucleotides. There are four types of nucleotides. Each nucleotide has three components; a phosphate group, a sugar and a base that contains nitrogen within its structure. The sugar moiety in DNA oligonucleotides is always dexoyribose, and there are four alternative bases: adenine (A), thymine (T), guanine (G), and cytosine (C). The phosphate groups and the deoxyribose sugars form the backbone of each DNA stand. The bases are joined to the deoxyribose sugar and stick out to the side. Both oligomers, DNA and RNA, consist of 5’->3’ phosphodiester-linked nucleotide units that are composed of a 2’-deoxy-D-ribose (DNA) or D-ribose (RNA) in their furanose forms and a heteroaromatic nucleobase (A, T, G, and C; A, U, G, C), and the resulting oligonucleotide chain is composed of a polar, negatively charged sugar-phosphate backbone and an array of hydrophobic nucleobases. The amphiphilic nature of these polymers dictates the assembly and maintenance of secondary and tertiary structures the oligonucleotides can form. In the DNA duplex structure, genetic information is stored as a linear nucleotide code. This code can be accessed and replicated. RNA, or ribonucleic acid, is another structurally related essential biopolymer. RNA differs from DNA in having the sugar ribose in place of the deoxyribos...
Hall, Linley Erin. “Understanding Genetics DNA and RNA.” New York: The Rosen Publishing Group, Inc., 2011. Print. 01 Apr. 2014.
Lurie, Susan. "Professor Ada Yonath Speaks on Ribosomes." Esra Magazine: n. pag. Esra Magazine. Web. 26 Nov. 2013. .
Describe the steps of protein synthesis beginning with the attachment of a messenger RNA molecule to the small subunit of a ribosome and ending with the release of the polypeptide from the ribosomes. Include in your answer a discussion of how the different types of RNA function in this process.
This article relates to this course about Biology within the cells. This article relates to
...Glass, Non-coding RNAs as regulators of gene expression and epigenetics, 2011, oxford journals, 90 (3), p430-440
There is a two step process involved in order for the genes to be used. The first half of this process is called transcription. DNA is made up of four nucleotides: adenine, cytosine, guanine, and thiamin. These nucleotides are in pairs in the DNA and their order is very important because it dictates how the gene will be expressed. During transcription RNA, a similar molecule to DNA, comes in and makes the compliment copy of the DNA sequence. The second half of this process is called translation. During translation the RNA is used to make amino acids, which are then used to make a protein. Not all of the RNA is used to make the amino acids, only the sections which are between the start and stop signals. Then sets of three nucleotides called codons are used to make specific amino acids. Different sets of amino acids code for different proteins.
POLYSOME. "Analysis of ribosome loading onto mRNA species: implications for translational control." mRNA Formation and Function (1997): 305.
Ribonucleic acid or RNA is a polymeric molecule made up of one or more nucleotides. A polymeric molecule is a very large molecule that is chain- like. It is made up of monomers, which are smaller molecules. A strand of RNA can be thought of as a chain with a nucleotide at each chain link. Whereas, a nucleotide is a group of any type of molecules that are linked together because they form the “building blocks” of DNA (also known as deoxyribonucleic acid, and it is the carrier of genetic information.) Messenger RNA, which is called mRNA, carries the genetic information copied from DNA. Transfer RNA, which is called tRNA is the key to deciphering the code words in mRNA that forms a series of three-base code words. An enzyme is a substance that
The process of translation is a major part of protein synthesis. There are many different components related the process of protein synthesis which include the large ribosomal unit, 60S and the small ribosomal unit,40S. As well as these are the messenger RNA, “mRNA coding”, transfer RNA , tRNA for amino acids and finally greater than 12 of the catalytic proteins which have be found to be eIFs (eukaryotic initiation factors). (Norton and Layman, 2006)These initiation factors are quite important in relation to Protein Synthesis and translation initiation. ...“These initiation factors guide the assembly of the ribosome on the mRNA and are responsive to short-term changes in the availability of energy, amino acids, and growth factors. Initiation factors provide the cell with sensitivity to environmental factors, including changes in diet, such as leucine availability, and physical activity.”... As well as this they also enable the cell to become sensitive to factors like the availability of
Thomas Cech’s most excellent contribution was the theory behind self splicing RNA. First of all, RNA also known as Ribonucleic Acid is a kind if nucleic acid that is generally single stranded. In addition, RNA plays a vital role for transferring information into protein forming system of the cell from the DNA (Deoxyribonucleic Acid). Thomas Cech has done his research in a laboratory. To briefly learn the contribution, Scientist Cech and his researched team first started with the process of how stored genetic information in DNA can be transcribed into a molecule known as mRNA (messenger RNA), which is further changed into a protein. In all kinds of living organisms, this process takes place. However, in plants and humans, the coding region of the DNA which is the exons are episodic by the nonbonding regions of the DNA which is the introns.
Translation is also a process that contains the RNA copy of DNA to make a protein. i.e the mRNA sequence is translated into a sequence of amino acids as a result protein is formed. During translation, RNA molecule is responsible
The amount of information encoded by the genes within a cell is enormous, although some will never be expressed while others occasionally during its life cycle. For example some genes that encode for ribosomal RNA are being expressed continuously because they are responsible with the formation of proteins in the cell’s cytoplasm. Specific RNA molecules and proteins are expressed in all cells at all times, their genes going under the name of housekeeping genes. They are responsible with the maintenance of the cells and can aid geneticists recognize their function (Brown, 2011).