Chromatin plays a central role in the conversion of energy in cells: alteration of chromatin structure to make DNA accessible consumes energy, and compaction of chromatin preserves energy. Alteration of chromatin structure uses energy sources derived from carbon metabolism such as ATP and acetyl-CoA; ...
In prokaryotes, the chromosome is typically a single loop of stable chromosomal DNA in the nucleoid, e.g. of a bacterial cell. Prokaryotic DNA is associated with non-histone proteins. In viruses, there is also no nucleus and so the chromosome may appear as a short linear or circular ...
Transcription of eukaryotic genes appears to proceed in a quite different manner and to obey very different rules than the corresponding process in prokaryotes. In a typical prokaryotic organism, the genome is small, and much of it is transcribed. Polycistronic messages are common, but intervening ...
Chromatin structure is highly complex and impressively dynamic. Scientists now realize that the nucleosome, which was once thought to be static, actually plays an integral role in directing some elements of transcriptional specification (Figure 1). ...
This structure may be associated with H1. A second level of organization is achieved through folding the 10 nm filament into a more compact state. In vitro, the 10 nm filament has been observed to spontaneously fold around a central axis into a uniform fiber of ∼30 nm diameter (the so...
DNA adenine methyltransferase (DAM) catalyzes the addition of a methyl group to the adenine base in the sequence GATC [16]. DAM activities are used by a number of bacterial phages and prokaryotes. In E. coli, DAM is involved in a multitude of cellular processes, including DNA replication, ...
The genomes of prokaryotes are contained in single chromosomes, which are usually circular DNA molecules. In contrast, the genomes of eukaryotes are composed of multiple chromosomes, each containing a linear molecule of DNA. Although the numbers and sizes of chromosomes vary considerably between ...
How does the structure of DNA allow cells to replicate? How does protein synthesis differ between prokaryotes and eukaryotes? What are the structures of RNA and DNA and how might one be used to create the other? What DNA virus replicates in cytoplasm? What binds to the prokaryotic c...
Eukaryotic genetic replication involves both DNA synthesis and chromatin assembly. Chromosomal DNA synthesis is similar to prokaryotic DNA replication in that each of the two strands serves as template for new synthesis. In contrast to the situation in prokaryotes, eukaryotic DNA replication is limited ...
(clustered regularly interspaced short palindromic repeats) arrays are a key element in the defense systems against foreign genetic material of many prokaryotes and consist of multiple identical repeats interspersed with non-repetitive sequences that target foreign plasmids and phages, together with a set...