Expressed in bacteria

Many proteins that switch off or on gene expression in bacteria are dimeric molecules, and the DNA sequences that they specifically recognize are palindromic at their ends. The twofold symmetry of the protein is therefore matched by twofold symmetry at the ends of the recognition sequence. 

Good L., Nielsen P.E. Antisense inhibition of gene expression in bacteria by PNA targeted to mRNA. Nature Biotech-nol. 1998 16 355-358. 

Williams, T. L. Leopold, P. Musser, S. Automated postprocessing of electrospray LC/MS data for profiling protein expression in bacteria. Anal. Chem. 2002, 74, 5807-5813. 

The other subfamily, SLC1, includes the Na+-dependent glutamate transporters. It encompasses some amino- and carboxylic-acid transporters including glutamate transporters that are expressed in bacteria. X-ray diffraction data have been obtained from crystals of one of these [43] (Fig. 5-13). Analysis of multiple sequence alignments indicates that this molecule has a high degree of structural... 

It has recently been shown that some phosphorylations may be useful only to activate a protein and once in its active form or complexed, phosphorylation is no longer needed (Scheme 3). Karwowska-Desaulniers et ak recently hypothesized that phosphorylation of histone deacetylase 1 (HDACl) at two key residues is important for complex formation of active protein in vivo. However, when the phosphorylation sites were mutated to alanine, no active protein was expressed, yet complex formation was still observed. Even when native protein was expressed and dephosphorylated, complex formation and activity were still observed. The complex formation is still not fully understood the complexes are thought to place HDAC in the correct position. No active noncomplexed HDAC has been generated in order to study the effects of complexation. Interestingly, when HDACl was expressed in bacteria and subsequently phosphorylated there was no... 

Post-translational modifications, such as phosphorylation, complex glycosylation, and lipidation, typically occur in eukaryotic organisms. Therefore, their expression in prokaryotic systems like Escherichia coli is difficult. However, it should be noted that via clever engineering and coexpression of specific enzymes, access can be granted to specific lipidated proteins via expression in bacteria, for example, via the expression of A -myristoyltransferase in E. coli Eukaryotic systems that can be used for the expression of post-translationally modified proteins are yeast and Dictyostelium discoidum. Furthermore, lipidated proteins, such as the Rah proteins, can be obtained via purification from tissue sources or from membrane fractions of insect cells that had been infected with baculovirus bearing a Rah gene. ... 

If the end goal of cloning is to have a cloned gene expressed in a cell, the entire coding sequence must be doned intact. Furthermore, if a cloned eukaryotic gene is to be expressed in bacteria (to make recombinant proteins), the gene must not contain introns, which could not be processed in a prokaryotic cell. In these cases it is more convenient to done cDNA rather than DNA restriction fragments. 

Several lines of evidence indicate that CENP-A replaces conventional H3 in the nucleosome. Biochemical studies showed that CENP-A co-sediments with nucleo-some core particles [7] and a genetic analysis indicates an interaction between Cse4p, the CENP-A of Saccharomyces cerevisiae, and H4 [16,17]. A recent study with CENP-A purified from HeLa cells or expressed in bacteria showed that it can substitute for conventional H3 in nucleosome reconstitution [18]. Reconstituted CENP-A-containing nucleosomes appear to contain the other core histones in appropriate stoichiometry. However, they did not strongly protect 146 bp of core DNA from micrococcal nuclease, suggesting that CENP-A may significantly alter some aspects of the core nucleosome structure. 

Human insulin (prb) recombinant human insulin in which proinsulin is expressed in bacteria... 

Prasad VR, Goff SP. Linker insertion mutagenesis of the human immunodeficiency virus transcriptase expressed in bacteria definition of the minimal polymerase domain. Proc Natl Acad Sci USA 1989 86 3104-3108. 

Desaturation takes place in a stepwise fashion, and many intermediate compounds with fewer double bonds are known (Eq. 22-10).118/121-123 The enzymes required have not been characterized well until recently. Plant enzymes are present in small amounts, and isolation has been difficult. However, the genes for carotenoid biosynthesis in such bacteria as the purple photosynthetic RhodobacterRhodospirillum,125 and Rubrivarax,126 the cyanobacterium Synechococcus,127 and the nonphotosynthetic Erwinia44/118 have been cloned, sequenced, and used to produce enzymes in quantities that can be studied. Matching genes from higher plants have also been cloned and expressed in bacteria.123... 

M. Brockman et al.,/. Chem. Educ. 73, 542-543 (1996). A biotech lab project for recombinant protein expression in bacteria. 

What kind of changes have to be made in a typical eukaryotic structural gene for its protein product to be expressed in bacteria ... 

Before attempting to purify a protein, the first thing to consider is the source of starting material. Proteins differ in their cellular and tissue distribution, and thus if a protein is known to be abundant in one particular tissue (e.g. kidney) it makes sense to start the purification from this source. Also, some sources are more readily available than others and this should be taken into account too. Nowadays, with the use of recombinant DNA techniques (see Topics II and 16), even scarce proteins can be expressed in bacteria or eukaryotic cells and relatively large amounts of the protein subsequently obtained. 

Recombinant human CYP enzymes expressed in bacteria (Bactosomes from Cypex) Recombinant human CYP enzymes expressed in insect cells (Supersomes from BD-Gentest) Chloromethyl fluorescein diethylether (216). 

The animal cell has a major advantage over the bacterial cell as the medium for expression of cloned mammalian genes. The transcript produced is processed and the protein produced is modified in the correct manner. This is seldom the case for mammalian genes expressed in bacteria. 

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