Why can we not reliably predict the sequence of nucleotides on mrna or dna?
The coding system from DNA to amino acids is redundant, meaning that some amino acids can have multiple codons (sets of 3 nucleotides) that code for them. You could get a decent idea of what it might look like, but definitely not 100%. For example if you have the amino acid serine, it could be coded for by a UCA, UCC, UCU, or UCG. Notice that they differ only in the last nucleotide. This is most likely so minor mutations in the DNA won't have that drastic of an effect on the proteins. If you have a UCA, and the A gets changed into a G, it will still code for serine. This is a silent mutation because it doesn't affect the production of the protein, which is a good thing for us.
Protein sequence encoded by genes/ BlastP?
The protein sequence encoded by the gene To do this you will have to find a website that will do a translation from nucleotide sequence to amino acid sequence for you - you are not expected to do a translation by hand! You should generate the amino acid sequence using the one-letter code for amino acids. Perform a BlastP search to identify the gene product with which you are working. Use the amino acid sequence that you got from the first analysis. Again, you will have to search around online a bit to find out what to do. Select the name of the gene that best matches the sequence you are testing. Gene A atggtgcacc tgactcctga ggagaagtct gccgttactg ccctgtgggg caaggtgaac gtggatgaag ttggtggtga ggccctgggc aggctgctgg tggtctaccc ttggacccag aggttccttg agtcctttgg ggatctgtcc actcctgatg ctgttatggg caaccctaag gtgaaggctc atggcaagaa agtgctcggt gcctttagtg atggcctggc tcacctggac aacctcaagg gcacctttgc cacactgagt gagctgcact gtgacaagct gcacgtggat cctgagaact tcaggctcct gggcaacgtg ctggtctgtg tgctggccca tcactttggc aaagaattca ccccaccagt gcaggctgcc tatcagaaag tggtggctgg tgtggctaat gccctggccc acaagtatca ctaa I translated the nucleotides on this website http://hcv.lanl.gov/content/sequence/TRANSLATE/translate.html And now, i'm supposed to do the second part of the question. What's a good website to use for the BlastP? I found one, but it found no matches when i put the translated nucleotides in. that website was: http://searchlauncher.bcm.tmc.edu/seq-search/protein-search-genomes.html Please help me find a site that will do this!! :) Thanks
If an extra nucleotide is added to an mRNA what will happen?
It depends upon where the changes take place. If the insertion or deletion of a single nucleotide takes place in the portion of the mRNA that encodes the information for a protein, then there would be a 'frameshift' mutation, changing the sequence of the protein that is being synthesized. Interestingly however, mRNA molecules have sequences beyond those that 'code' for the protein. These 'untranslated' sequences can influence the stability of the mRNA, how quickly it gets translated, and a number of other things. Changes in these regions of the mRNA will not change the synthesis of the protein at all.
What would happen when one nucleotide pair is lost from the middle of the coding sequence gene?
When RNA is translated into protein, it does so in 3-nucleotide groups, called codons. The ribosome starts at the beginning (at a specific sequence), then translates 3 nucleotides at a time, regardless of whether or not they are the "correct" codons. For example, take this sentence, broken up into 3-letter 'codons': the cat ate the rat If you were to have a deletion mutation near the beginning (let's say the first 'c'), then the rest of the phrase would be thrown out of alignment and the ribosome would read: the ata tet her at You can see that when the 'c' is deleted, the rest of the sequence shifts forward and re-established 3-letter codons. Since the ribosome has no way of knowing the proper code or what the protein should look like, it just trundles along, and reads whatever is in front of it. Note that it only affects the sequence downstream of the mutation. These sorts of frame shift mutations can be 'rescued' by an insertion mutation. If we cause a point mutation to place a 'c' back in at a different location (let's say at the beginning of the 3rd codon), you'd get: the ata cte the rat There's still a little bit of gibberish in the middle, but if most of the protein's sequence is restored, sometimes it can retain proper function. The same is true if the original deletion is followed by 2 more deletions. It will result in the net loss of one codon (one amino acid), and part of the sequence can still be shifted out of frame, but if the deletions are close enough together it can save the protein.
What might happen if a mutation occurs in the promoter sequence of a gene ?
The promoter sequence is usually distinct from the coding region. The coding region is where the 3-letter codes for amino acids (the building blocks of proteins) are. If there is a deletion in this region that is not a multiple of 3, a frame-shift could occur that causes the code to be misaligned and the protein will not be properly made. The promoter sequence is usually DNA in front of or behind the coding region that recruits DNA binding proteins needed to start transcription (or RNA making). So, the promoter sequence just needs to have the sequence that the DNA binding proteins need to recognize the promoter as something they want to bind to. If your deletion in a region that the DNA binding proteins don't need, probably nothing will happen. If your deletion is in a region needed for the DNA binding proteins to recognize the promoter, the binding proteins will no longer bind and transcription machinery won't get recruited to the gene and likely no RNA and thus no protein will be made. So how likely you will see no protein being made depends on how many regulatory sequences your promoter has and how big your deletion is.
How could one change in a DNA nucleotide alter the formation of the translated protein?
Is your question about DNA nucleotide sequence? That if one DNA nucleotide in a sequence changes, it could alter the type of the protein translated? As you know, a group of three nucleotide is called a codon. Each codon has its own specific translated amino acid. For example, AUG is the codon for methionine. However, one amino acid might apply for many codons. In this case, the type of mutation is a missense mutation, where another amino acid is translated when a nucleotide is either substituted, inserted or deleted. Sickle cells occur when one of the nucleotides in what would have been a normal cell is substituted, resulting in a different amino acid and ultimately, a defective protein that is the sickle cell hemoglobin. I think this case where glutamic acid would have occupied a spot in a normal cell protein, it is replaced by valine because of the substitution of adenine with thymine. However the most destructive types of point mutation are insertion and substitution. This is because if a single nucleotide is inserted or deleted, particularly near the 5' of the DNA strand, the subsequent translations for the amino acids will be altered. Some cause diseases and disabilities to the child, while others might result in nonfunctional proteins and even kill him/her.
There is a mutation in a DNA sequence. However, that mutation does not change the amino acid sequence. What type of mutation is this?
The mutation occured at gene level it has possibilities that the small change in tbe DNA sequence may be corrected during the translation by DNA polymerase due to this the amino acids sequenceing doesn't be affected.DNA pollymerase is enzyme which check and corrects the gene sequencing if at that level it is not be corrected than it is effective at atbe other level i.e phenotypic level.
What is a segment of DNA that codes for a protein?
There are 3 good answers but I was asked to add to this topic so I can amplify a little. A "gene" might be a regulatory gene which does not code for protein, there are all sorts of genes. There are genes for tRNA, rRNA, etc. An ORF or open reading frame is an exact match to the question -- ORF's code for protein even though some of them never produce an actual protein in the cell. One of the differences between a STRUCTURAL gene (which produces a protein) and an ORF is that there is some other stuff that makes a gene get expressed -- for example there has to be a promoter region (in bacterial DNA) which "attracts the attention" of RNA Polymerase. Some ORF's have no promoter so they never get made into RNA. There has to be a ribosome binding site (in bacteria) so that once you DO transcribe the DNA into mRNA, the ribosome will "get interested" in making protein from it. An ORF could easily lack that. I will admit that I am no expert on eukaryotic expression -- the chromatin structure makes things much more difficult. And I think there are lots of transcription factors etc. that have to be in the right place to make the gene expression happen.
How can a mutation in DNA affect the protein that is built from a specific gene sequence?
DNA codes for proteins. So, if the DNA is mutated, it directly affects the protein. Two examples of mutations are: A point mutation. In this situation, one base pair (A, T, C, or G) is replaced with a different, incorrect one. When this happens and the DNA is read in order to synthesize a protein, this incorrect base pair can lead to the DNA codon (set of 3 base pairs) that codes for a different base pair than it should have. This causes the protein to have one incorrect amino acid in it. Also, this mutation does not always mutate the protein because some codons code for the same amino acid. A frame shift mutation. This type is much worse. In this case, a base pair is just inserted in to the DNA sequence. When this happens, the entire sequence following it is essentially pushed over one spot. Then, each set of 3 base pairs that would code for an amino acid is shifted so that, instead, you would have something like 2 base pairs and 1 base pair from the codon next to it. This causes every single codon to mutate, which essentially leads to every amino acid being different and therefore, the entire protein being different. I hope that made sense. Diagrams help.
What happens when a DNA code is changed?
Well when DNA code is changed the scienific anatomy of the celluar molecity is transfused in pi and then pi is converted into one of those weird asian letter tattoos that people get but yet no one else knows what they mean.. I mean seriously people at tatoo parlors are dumb they could just lie to u about what it says to play a sick joke... but back to the question after the DNA is changed a tiny lepracaun named reilly o'reilly shows up at your door step and then tells u to throw the cleotard yes the cleotard