molecules necessary for protein ..

RNAs involved in protein biosynthesis
Information flow in the cell: DNA is transcribed to mRNA which is translated (decoded as) into Protein. Protein biosynthesis takes place in the ribosomes. A series of ribosomes (poly ribosome) can simultaneously translate the same eukaryotic mRNA molecule. tRNA brings specific amino acid to ribosome and mRNA carries the genetic information to protein. Codons that encode the same amino acid often differ only by their third base. The binding of the third base is less stringent than the other two. Because of this wobble, one tRNA can pair with multiple mRNA codons.

Protein Biosynthesis - Purdue University

Explain the steps involved in biosynthesis of protein, including the roles of RNA

it isn't involved in the process by which the ..

The involvement of the two glycosyltransferase auxiliary proteins in spiramycin biosynthesis was also elucidated. Our results showed that both of them are involved in glycosylation. The two glycosyltransferases Srm5 and Srm29 require the assistance of an auxiliary protein to perform the attachment of mycaminose and forosamine, respectively. The genes encoding these glycosyltransferases are both immediately downstream of the genes encoding the auxiliary proteins. Each glycosyltransferase can be activated by the auxiliary protein encoded by the upstream gene: Srm5 by Srm6 and Srm29 by Srm28. In addition, we have demonstrated the existence of an interplay between the auxiliary proteins (i.e., Srm28 can also efficiently activate Srm5). This explains why srm6 is dispensable for spiramycin biosynthesis. In contrast, we did not observe any activation of Srm29 by Srm6. Because of the observed flexibility of auxiliary proteins, we cannot exclude that Srm38, the mycarosyltransferase, might require the assistance of an auxiliary protein, but this cannot be studied in vivo in S. ambofaciens.

Steps involved in protein synthesis are ..

There are three deoxysugar moieties in the spiramycin molecule: two amino sugars, mycaminose and forosamine, and one neutral sugar, mycarose (Fig. ). Enzymes involved in the biosynthesis of these sugars are encoded by genes in the spiramycin biosynthetic gene cluster (). The analysis of the cluster revealed the presence of four genes (srm5, srm29, srm30, and srm38) encoding putative glycosyltransferases () (Fig. ). This was unexpected as there is usually one specific glycosyltransferase for each sugar to be transferred. To explain the discrepancy between the number of putative glycosyltransferases and the number of sugar moieties, several hypotheses can be formulated. For instance, one of these genes might not be expressed. However, transcriptional analysis of the cluster showed that all four genes are transcribed during spiramycin biosynthesis, and their transcription is coregulated with that of the other biosynthetic genes (F. Karray et al., unpublished data). Alternatively, the product of one of the genes might be inactive, but comparisons and alignments with the protein sequences of functional glycosyltransferases did not provide any obvious indication that this might be the case. In that light, if all of the glycosyltransferases are expressed and active, two of them could independently catalyze the attachment of the same sugar. Finally, one of the four glycosyltransferases may be involved in a process other than spiramycin biosynthesis, for instance, in macrolide resistance by drug inactivation, which has been observed in Streptomyces antibioticus, a producer of the macrolide oleandomycin ().

05/06/2012 · Explain the steps involved in biosynthesis of protein including the roles of RNA?
04/01/2014 · Major steps involved in mechanism of Protein Synthesis are 1. Transcription and 2. Translation! Biosynthesis of protein is …

Protein biosynthesis - Wikipedia

As Srm28 possesses certain flexibility, it would be interesting to determine if it can efficiently activate other glycosyltransferases requiring the assistance of auxiliary proteins. It was shown that different auxiliary proteins could activate the DesVII glycosyltransferase, but the efficiency of the activation ranged between 26 and 66% compared to that of the natural partner DesVIII (). To our knowledge, this is the first report of the interplay of auxiliary proteins involved in different glycosylation steps during the synthesis of a single compound, but the auxiliary proteins studied thus far have been involved in pathways where only one glycosyltransferase required the assistance of an auxiliary protein. Other macrolide biosynthetic pathways may also involve two auxiliary proteins with two glycosyltransferases that require them. One such example might be the megalomicin biosynthetic pathway. Megalomicin, which is produced by Micromonospora megalomicea, is structurally very similar to erythromycin but differs by the addition of the deoxyamino sugar megosamine, attached at the C-6 of the macrolactone. In the megalomicin biosynthetic cluster, there are two genes located immediately upstream of the mycaminosyltransferase and megosaminyltransferase genes, which are predicted to code for auxiliary proteins though they were originally annotated as nucleoside diphosphate (NDP)-sugar epimerases (, ). It would be interesting to investigate the role and eventual interplay of the putative auxiliary proteins in this pathway.

A typical cell requires thousands of different protein molecules at ..

Biochemistry: Protein Biosynthesis - Rapid Learning Center

One of the most common resistance mechanisms to macrolide antibiotics encountered in pathogenic bacteria involves target modification. These modifications could include mutation or methylation of the 23S residues involved in the interaction with macrolide antibiotics (, , ). Molecular modeling helped to explain how these modifications could hamper the binding of macrolides to modified ribosomes (, ). Taken together, these studies suggested that modification of the glycosylation pattern of macrolides was a way to obtain new macrolides with enhanced or modified affinities for their targets, which could help to circumvent some resistance mechanisms. As a consequence, many studies were undertaken to characterize the biosynthetic pathways of the sugars present in macrolides and the glycosyltransferases involved in their attachment to the macrolactone ring (for a review, see references , , and ). The resulting knowledge was applied for the generation of novel compounds by combinatorial biology (, ). To be successful, these approaches rely on the availability of macrolide glycosyltransferases with a certain degree of substrate flexibility regarding the sugar donor and/or the aglycone acceptor. In this perspective, it is interesting to characterize the glycosyltransferases involved in the glycosylation of various macrolide antibiotics.

Protein biosynthesis takes place in the ..

Learn what is protein synthesis

To understand how proteins are made, we have to divide thedecoding process into two steps. DNA only stores the geneticinformation, it isn't involved in the process by which theinformation is used. The first step in protein biosynthesistherefore has to involve transcribing the information inthe DNA structure into a useful form. In a separate step, thisinformation can be translated into a sequence of aminoacids.