Molecular Biology Lecture III Prof. Graham Walker Video | DnaTube ...
This is what's known as the leading strand because DNA, the synthesis of the new strand can go -- Which is going 5 prime to 3 prime is going in the same direction as the movement of the replication fork. ... nAnd it's continually jumping. And I told you that the little RNA primer is used to start each strand. And then the DNA polymerase is able to elongate that. And then at the end these little nicks in here, the RNA has to be removed, fill in the gap and then it's sealed [more...]
Date: 2009-02-04 08:00:00
The Biotechnology of Cannabis sativa! - 420 Magazine
diploid. This means that it has two copies of each chromosome. By comparison, humans have 23 chromosomes and are diploid. Genes along the DNA strand code for the proteins that direct cellular development, flower development, etc. This is discussed in more detail later, since it deserves its own chapter. All of these botanical features and how they relate to Cannabis have not been described in vain. They serve as a platform for the remainder of this book and facilitate a robust background to host extending ideas on the genetic modification of Cannabis. ! *$! 2. Plant [more...]
Date: 2010-08-30 01:54:17
Space travel 21st century: Michael Jackson
Histone proteins bind linear DNA strands and compress them into nuclear complexes, collectively referred to as chromatin. Karlseder and O'Sullivan found that aging cells simply made less histone protein than do young cells. "We were surprised to find that histone levels decreased as cells aged," said O'Sullivan, the study's first author. "These proteins are required throughout the genome, and therefore any event that disrupts this production line affects the stability of the entire genome." The team then undertook exhaustive "time-lapse" comparisons of histones in young versus aging cells and [more...]
Date: 2010-10-08 00:38:00
Biology Direct | Full text | Presence of a classical RRM-fold palm ...
However, the archaeal HtRNA possesses a cytosine and the archaeal Thg1 elongates the 5' end in a template-dependent manner . Furthermore, this 3'-5' template-dependent polymerization has also been demonstrated for the yeast enzyme when supplied with the appropriate cytosine-containing templates . The Thg1 polymerization reaction has been shown to be processive in terms of being able to add further nucleotides in the 3'-5' direction, if appropriate templates are supplied. Accordingly, it has been proposed that this polymerase activity is likely to have been the ancestral activity of the [more...]
Date: 2010-06-17 07:00:00
NIST Tech Beat - April 7, 2009
(A) Schematic of the NIST-Cornell nanofluidic device with complex 3-D surfaces. Each “step” of the “staircase” seen on the side marks a different depth within the chamber. The letter “E” shows the direction of the electric field used to move the nanoparticles through the device. The green balls are spheres with diameters of 100 nanometers whose size restricts them from moving into the shallower regions of the chamber. The coil in the deep end of the chamber (upper right corner) is a single DNA strand that elongates (upper left corner) in the shallow end. (B) Photomicrograph [more...]
Date: 2009-04-07 21:34:48
PLoS Biology: Elongated Polyproline Motifs Facilitate Enamel ...
Tianquan Jin1#, Yoshihiro Ito1#, Xianghong Luan1, Smit Dangaria1, Cameron Walker1, Michael Allen2, Ashok Kulkarni3, Carolyn Gibson4, Richard Braatz5, Xiubei Liao6, Thomas G. H. Diekwisch1*1 Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago College of Dentistry, Chicago, Illinois, United States of America, 2 University of Chicago, Chicago, Illinois, United States of America, 3 National Institutes of Health, Functional Genomics Unit, Bethesda, Maryland, United States of America, 4 University of Pennsylvania, Philadelphia, Pennsylvania, United States of America, 5 [more...]
Date: 2009-12-22 08:00:00
PLoS Pathogens: Three Dimensional Structure of the MqsR:MqsA ...
Breann L. Brown1#, Simina Grigoriu2#, Younghoon Kim3, Jennifer M. Arruda2, Andrew Davenport1, Thomas K. Wood3,4,5, Wolfgang Peti1, Rebecca Page2*1 Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, Rhode Island, United States of America, 2 Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, United States of America, 3 Artie McFerrin Department of Chemical Engineering, Texas A & M University, College Station, Texas, United States of America, 4 Department of Biology, Texas A & M University, [more...]
Date: 2009-12-24 08:00:00
Errors in First Aid for the USMLE (2007): Biochemistry « the ...
Within the replication bubble, only the lagging strand creates fragments. The description of DNA poly III elongating “until it reaches primer of preceding fragment,” while true for one leading strand meeting another replication bubble, confuses the issue here. I think it could read: “On the leading strand, elongates the chain by adding deoxynucleotides to the 3′ end until it reaches another replication bubble. When on the lagging strand, it performs the same action repeatedly as the replication bubble grows, creating Okazaki fragments.” This would of course have to be preceded by an [more...]
Date: 2007-01-17 05:28:52
BioData Mining | Full text | Multifactor dimensionality reduction ...
This allows the finger domain to interact with the minor groove of the elongating strands, thereby reading the conformation of downstream base-pairing. Also, the templating strand diverts the next template base from the active site, fostering correct template reading on the part of the polymerase. Not surprisingly, polymerase amino acid side-chain interactions play a critical role in efficiency and fidelity. In the case of polymerase β (pol β), Wilson and colleagues found that Asp-276 and Lys-280 form stacking interactions with the incoming nucleotide and the template, with their [more...]
Date: 2009-03-30 07:00:00
Strange things at promoters « The RNA Underworld
The idea is that bisulfite treatment converts C’s to U’s; after cDNA synthesis and sequencing of treated RNAs (again by Solexa sequencing), the sequences will only match one of the two strands of the corresponding gene, and only after the gene has been “modified” by the computer. The theme that runs through these four papers is fascinating, as it suggests that transcription may proceed bidirectionally at most promoters, even those that are not parts of bidirectional transcription units (pairs of adjacent genes that are transcribed into translated RNAs in opposite directions). The [more...]
Date: 2008-12-13 16:04:22
PLoS Computational Biology: A Quantitative Study of the Division ...
Abstract TopProgression of a cell through the division cycle is tightly controlled at different steps to ensure the integrity of genome replication and partitioning to daughter cells. From published experimental evidence, we propose a molecular mechanism for control of the cell division cycle in Caulobacter crescentus. The mechanism, which is based on the synthesis and degradation of three “master regulator” proteins (CtrA, GcrA, and DnaA), is converted into a quantitative model, in order to study the temporal dynamics of these and other cell cycle proteins. The model accounts for [more...]
Date: 2008-01-25 08:00:00
The RNA polymerases can add only RNA nucleotides to the 3’ end of the strand, so RNA elongates in the 5’ to 3’ direction.The DNA sequence at which RNA polymerase attaches is called the promoter sequence. The DNA sequence that signals the end of transcription is called the terminator. The entire stretch of DNA that is transcribed into mRNA is called a transcription unit. There are 3 main stages of transcription: 1. Initiation: In prokaryotes, a group of proteins plus RNA polymerase, bound to the promoter region of a DNA sequence, is collectively known as a transcription initiation [more...]
Date: 2009-01-15 04:31:00
$1.00 - Bio2010
DNA polymerase I catalyzes the elongation of the new DNA strands in prokaryotes. c. The lagging strand is synthesized as Okazaki fragments. d. The leading strand elongates from its 3' to 5' end. e. Helicases initiate replication by winding the two strands together. Save Answer 16. (Points: 5) The appropriate adjective to describe DNA replication is a. progressive. b. lytic. c. semiconservative. d. nondisruptive. e. natural. Save Answer 17. (Points: 5) In a sample of double-stranded DNA from a human, you have determined that 20 percent of the nitrogenous base is adenine. What percentage should [more...]
Date: 2008-08-05 01:50:23
DNA Polymerase and other factors
DNA polymerase can add free nucleotides to only the 3’ end of the newly-forming strand. This results in elongation of the new strand in a 5'-3' direction. No known DNA polymerase is able to begin a new chain (de novo). DNA polymerase can add a nucleotide onto only a preexisting 3'-OH group, and, therefore, needs a primer at which it can add the first nucleotide. Primers consist of RNA and DNA bases with the first two bases always being RNA, and are synthesized by another enzyme called primase. An enzyme known as a helicase is required to unwind DNA from a double-strand structure to a [more...]
Date: 2008-07-27 11:03:00
using RNA-seq Candida albicans fungal pathogen Comprehensive ...
Vincent M. Bruno,1 Zhong Wang,2 Sadie L. Marjani,3 Ghia M. Euskirchen,4. Jeffrey Martin,2 Gavin Sherlock,4,5 and Michael Snyder1,4,5. 1Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520, ...... Strand-specific. cDNA libraries were prepared as described by Parkhomchuk et al. (2009). About 30 nt of sequence was determined from one end of each cDNA fragment using high-throughput DNA sequencing. (Bentley et al. 2008). [more...]
Date: 2010-09-01 17:56:07
Plant DNA Recombinases: A Long Way to Go
Mutants sensitive to DNA damaging agents like UV and ionizing radiation showed deficiency in recombination . The complex nature of the process and crosstalk between homologous recombination and other pathways like transcription, repair , ... At this stage, the newly formed double stranded DNA has the old parental strand and a new incoming strand. It is therefore called heteroduplex. These heteroduplexes further extended to mediate complete strand exchange . [more...]
Date: 2009-12-14 03:07:53
Knot in the ribbon at the edge of the solar system “unties ...
Plasmoids appear to be plasma cylinders elongated in the direction of the magnetic field. Plasmoids possess a measurable magnetic moment, a measurable translational speed, a transverse electric field, and a measurable size. .... Mr. Evans, yes, but the plasmoid is only a fleeting thing; it is not a stable structure. rational debate says: October 1, 2010 at 5:15 pm. Come on folks, its plain as day. The ribbon is the solar system's equivalent of DNA or mDNA, [more...]
Date: 2010-10-01 07:01:15