分子生物學(Molecular Biology)

What came first the DNA or protein? Discovery of ribozymes and the hypothesis of RNA world has given this question another dimension. Enzyme was the only known natural catalysts to the discovery of ribozymes.

Ribozymes (also known as RNA enzyme or catalytic RNA) are RNA particles that catalyze biochemic reaction. Thomas Cech and Altman were the first to discover ribozymes during 1980s and went on later to investigate the catalytic properties. Thomas Cech found that splicing of introns in a ribosomal RNA in ribosomal RNA gene in Tetrahymena thermohila were found to occur in the absence of additional cell extract. Sidney Altman and his colleagues, separated the bacterial RNase P, an enzyme responsible for changing a precursor to active tRNA. However it was found that in addition to the protein, the enzyme also contained RNA that could stimulate the cleavage of precursor tRNA into tRNA in the absence of protein component. Also, Thomas Cech gave the conclusion that the intron sequence of the RNA can break and reform phosdiester bonds. They won the Nobel Prize in chemistry for the same thing in 1989. Natural ribosomes catalyze the hydrolysis of their own phosphodiester bonds. They also catalyze the aminotransferase activity. They also catalyze the hydrolysis of the other RNA. Ribozymes are so called because they act as enzymes in terms of their specificity and belong to RNA. However, they are different from enzymes because of the following reasons:

1) Unlike enzymes, ribozymes do not require specific pH and temperature
2) Ribozymes consists of nucleotides.
3) They do not have well defined regions, such as active site and catalyzed site.
4) They can act on a very small amounts of substances but perform a more limited set of instructions

A number of ribozymes have been discovered till date. The discovery of naturally occurring ribozymes is increasing, along with which several artificial ribozymes have also been synthesized. Due to their abilities, ribozymes have been investigated for applications as therapeutic agents, biosensors, and in genomics functions and discovery of genes.

What came first the DNAor protein? DiscoveryThe discovery ofribozymes and the hypothesis of RNA world has given this question another dimension. EnzymeBefore thediscovery of the ribozymes, enzymes was the only known naturalcatalyststo the discovery of ribozymes. . 1

Ribozymes (also known as RNA enzymeenzymesor catalytic RNA) are RNA particles that catalyze biochemic reaction.2biochemicalreactions. Thomas Cech and Sidney 3Altman were the first to discoverribozymes during the 1980s and later went on later toinvestigate thetheir catalyticproperties. Thomas Cech found that splicing of introns in a ribosomal RNA in the ribosomal RNA gene in Tetrahymena thermohila were found to occurthermophila occurred4in the absence of additional cell extractextracts. SidneyAltman and his colleagues, separated discovered 5thebacterial RNase P, an enzyme responsible for changing aconvertingprecursor tRNAto its active tRNA form6.However,it was found that in addition to the proteinproteins, the enzymealso containedRNA that could stimulate the cleavage of precursor tRNA into tRNA in theabsence of theprotein component. Also, ThomasIn addition, Cech gave the conclusionconcludedthat the intron sequence of the RNA can breakcould cleaveand reform phosdiesterphosphodiesterbonds.7 They won the Nobel Prize in chemistry for the same thing in 1989. Natural ribosomes ribozymes 8catalyzethe hydrolysis of their own phosphodiester bonds. They also catalyze the aminotransferase activity. They also Further, they catalyze the hydrolysis of the other RNA. RibozymesThey are so calledtermed as ribozymes becausethey actare as specificas enzymesin terms of their specificity and belong to RNA. However, they aredifferent from enzymes because of the following reasons:

1)Unlikeenzymes, ribozymes do not require a specific pH and temperature.

2)Ribozymesconsistsof nucleotides.

3)They do nothave well-defined regions, such as active site andcatalyzedcatalytic sites.

4)They can acton a verysmall amounts of substances but perform a more limited set of instructionsactions.

A number ofMany ribozymes have been discovered till date. The discovery of naturally occurringribozymes is increasing, along with whichthe synthesisof several artificial ribozymes have also been synthesized. Due to. Because of theirabilities, ribozymes have been investigated forapplications as therapeutic agents and biosensors as well as and ingenomicsfunctions and discovery ofgenes.

What came first: the 1DNA or protein? DiscoveryThe discoveryof ribozymes and the RNA world hypothesisof RNA world hashave provided a new perspective togiven this question another dimension.EnzymeBefore thediscovery of the ribozymes, enzymes waswere the only known natural catalysts to thediscovery of ribozymes. 2.

Ribozymes (also known as RNA enzymeenzymesor catalytic RNA) are RNA particles that catalyze biochemic reaction.biochemical reactions.3 Thomas Cech and Sidney 4Altman, who were the first to discoveredribozymes duringin the 1980s,and later went on later to investigatesubsequently studied thetheircatalytic properties. Thomas 5Cech found that when additional cell extract was absent, the splicing of introns in a ribosomal RNA in the ribosomal RNA genes in Tetrahymena thermohila were found to occur Tetrahymena thermophila 6underwent splicing occurredin the absence of additional cell extractextracts.Sidney Altman and hiscolleagues, separated discovered 7thebacterial RNase P, an enzyme responsible for changing aconvertingprecursor tRNAto its active tRNA form8.However,it was found that in addition to the proteinproteins,the enzyme alsocontained RNA that could stimulate the cleavage of precursor tRNAinto tRNA in the absence of the protein component. Also, ThomasIn addition, Cech gave the conclusionconcludedthat the intron sequence of the RNA can breakcould cleave andreform phosdiesterphosphodiesterbonds. 9They Cechand Altman10   won the Nobel Prize in chemistry for the same thingthis11in 1989. Naturalribosomesribozymes 12catalyze the hydrolysis oftheir own phosphodiester bonds. They also catalyze and other RNA sequences. They also catalyze the aminotransferase activity of the ribosome13. They also Further, they catalyze the hydrolysis of the other RNA. RibozymesThey are so calledtermed as ribozymes becausethey actare as specificas enzymesin terms of their specificity and belong to RNA. However,14Despite possessing enzymatic activity, they are differentribozymes differ from otherenzymes because of the following reasons:

1)Unlikeenzymes, ribozymes do not require a specific pH and temperature to function.

2)RibozymesconsistsThey consistof nucleotides.

3)They do nothave well-defined regions, such as active site and catalyzed sitecatalytic sites.

4)They can acton a veryextremly small amounts of substances but performa more limited set of instructions.

A number ofTo date, mMany natural ribozymes have been discovered and severalartificial ribozymes have been synthesized 15till date. The discovery of naturally occurring ribozymes isincreasing,along with whichthe synthesisof several artificial ribozymes have also been synthesized. Due to. Because of theirabilities, ribozymes have been investigated forapplications as therapeutic agents andbiosensors as well as in genomicsgenomicaddition to their functionsin genomics and gene discovery of genes.