A simple novel method for the preparation of noncovalent homodimeric, biologically active human interleukin 10 in Escherichia coli—Enhancing protein expression by degenerate PCR of 5′ DNA in the open reading frame

2008 ◽  
Vol 62 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Shelley Klompus ◽  
Gila Solomon ◽  
Arieh Gertler
2002 ◽  
Vol 184 (1) ◽  
pp. 51-58 ◽  
Author(s):  
E. Suzanne Paterson ◽  
Sherri E. Boucher ◽  
I. B. Lambert

ABSTRACT In Escherichia coli, the response to oxidative stress due to elevated levels of superoxide is mediated, in part, by the soxRS regulon. One member of the soxRS regulon, nfsA, encodes the major oxygen-insensitive nitroreductase in Escherichia coli which catalyzes the reduction of nitroaromatic and nitroheterocyclic compounds by NADPH. In this study we investigate the regulation of nfsA in response to the superoxide generating compound paraquat. The transcription start site (TSS) of nfsA was located upstream of the ybjC gene, a small open reading frame of unknown function located directly upstream of nfsA, suggesting that these two genes form an operon. The activity of the promoter associated with this TSS was confirmed with lacZ fusions and was shown to be inducible by paraquat. Footprinting and band shift analysis showed that purified His-tagged SoxS protein binds to a 20-base sequence 10 bases upstream of the −35 promoter sequence in the forward orientation, suggesting that the ybjC-nfsA promoter is a class I SoxS-dependent promoter.


1990 ◽  
Vol 10 (7) ◽  
pp. 3727-3736
Author(s):  
B Leiting ◽  
I J Lindner ◽  
A A Noegel

Dictyostelium discoideum plasmid Ddp2 from the wild strain WS380B is a 5.8-kilobase (kb) supercoiled circle with a copy number of 300 per haploid genome. We previously described the construction of an extrachromosomally replicating transformation vector pnDeI carrying 4.7 kb of Ddp2 sequences (B. Leiting, and A. Noegel, Plasmid 20:241-248, 1988). In order to reduce the sequences required for extrachromosomal maintenance in D. discoideum, we characterized Ddp2 by sequence analysis, by deletion experiments, by transcription mapping, by electrophoretic mobility shift assays, and by expression of its single open reading frame in Escherichia coli. Two elements were involved in replication of Ddp2: a cis-acting sequence located on a 592-base-pair (bp) fragment that consisted of 220 bp of essential and 372 bp of auxiliary sequences, and a 2.7-kb open reading frame which most likely encodes a trans-acting factor. The cis- and trans-acting elements did not overlap and were shown to act independently from the location of the sequences encoding the trans-acting factor.


2000 ◽  
Vol 182 (21) ◽  
pp. 6243-6246 ◽  
Author(s):  
Haitao Zhang ◽  
George T. Javor

ABSTRACT The open reading frame at 86.7 min on the Escherichia coli chromosome, “yigC,” complemented aubiD mutant strain, AN66, indicating that yigCis the ubiD gene. The gene product, a 497-amino-acid-residue protein, showed extensive homology to the UPF 00096 family of proteins in the Swiss-Prot database.


2019 ◽  
Vol 41 (11) ◽  
pp. 1293-1299 ◽  
Author(s):  
Eun-Ji Ko ◽  
Young Lim Oh ◽  
Heung Yeol Kim ◽  
Wan Kyu Eo ◽  
Hongbae Kim ◽  
...  

1998 ◽  
Vol 335 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Yin-yuan MO ◽  
J. SESHU ◽  
Dong WANG ◽  
Louis P. MALLAVIA

FK506-binding proteins (FKBPs) have been identified in a variety of eukaryotic and prokaryotic organisms. Macrophage infectivity potentiator (CbMip, 23.5 kDa) protein of the obligate intracellular bacterium, Coxiella burnetii, was shown previously to belong to the family of FKBPs based on sequence homology and peptidyl-prolyl cis/trans isomerase (PPIase) activity. Further characterization of the cbmip gene has identified two additional proteins with molecular masses of 15.5 and 15.0 kDa that are synthesized, in addition to the 23.5 kDa CbMip, when expressed in Escherichia coli. Amino acid sequencing at the N-terminus combined with transcription and translation fusion expression revealed that the two proteins were synthesized from the same open reading frame of the cbmip gene, but starting at different internal translation start codons, probably by translational reinitiation. When the internal methionines serving as start sites were replaced with lysine by site-directed mutagenesis, the synthesis of 15.5 and 15.0 kDa proteins was abolished even though the synthesis of 23.5 kDa CbMip was intact. This confirmed that the 15.5 and 15.0 kDa proteins are indeed generated by translational reinitiation and are not degradation products of the 23.5 kDa protein. Like other FKBPs, both 15.5 and 15.0 kDa proteins exhibit PPIase activity. Because they share significant sequence homology with FKBPs and have a similar PPIase activity, 15.5 and 15.0 kDa proteins are designated as C. burnetiiFKBP (Cb-FKBP) analogues I and II, respectively. TnphoA mutagenesis demonstrated that whereas the large protein (CbMip) is secreted, Cb-FKBP analogues I and II are cytoplasmic, indicating that structural variations could allow for different subcellular compartmentalization of similar proteins. Western-blot analysis of lysates of purified C. burnetii using a CbMip-specific monoclonal antibody revealed the presence of a protein migrating at ≈ 15 kDa, indicating the presence of smaller Cb-FKBP analogue(s) in C. burnetii, although at much lower levels compared with 23.5 kDa CbMip. This unique gene organization seen with cbmip may provide the organism with a mechanism of efficient use of its limited genetic information to synthesize proteins that are structurally different yet functionally similar.


2004 ◽  
Vol 70 (3) ◽  
pp. 1570-1575 ◽  
Author(s):  
Dae Heoun Baek ◽  
Jae Jun Song ◽  
Seok-Joon Kwon ◽  
Chung Park ◽  
Chang-Min Jung ◽  
...  

ABSTRACT A new thermostable dipeptidase gene was cloned from the thermophile Brevibacillus borstelensis BCS-1 by genetic complementation of the d-Glu auxotroph Escherichia coli WM335 on a plate containing d-Ala-d-Glu. Nucleotide sequence analysis revealed that the gene included an open reading frame coding for a 307-amino-acid sequence with an M r of 35,000. The deduced amino acid sequence of the dipeptidase exhibited 52% similarity with the dipeptidase from Listeria monocytogenes. The enzyme was purified to homogeneity from recombinant E. coli WM335 harboring the dipeptidase gene from B. borstelensis BCS-1. Investigation of the enantioselectivity (E) to the P1 and P1′ site of Ala-Ala revealed that the ratio of the specificity constant (k cat /Km ) for l-enantioselectivity to the P1 site of Ala-Ala was 23.4 � 2.2 [E = (k cat /Km ) l,d /(k cat /Km ) d,d ], while the d-enantioselectivity to the P1′ site of Ala-Ala was 16.4 � 0.5 [E = (k cat /Km ) l,d /(k cat /Km ) l,l ] at 55�C. The enzyme was stable up to 55�C, and the optimal pH and temperature were 8.5 and 65�C, respectively. The enzyme was able to hydrolyze l-Asp-d-Ala, l-Asp-d-AlaOMe, Z-d-Ala-d-AlaOBzl, and Z-l-Asp-d-AlaOBzl, yet it could not hydrolyze d-Ala-l-Asp, d-Ala-l-Ala, d-AlaNH2, and l-AlaNH2. The enzyme also exhibited β-lactamase activity similar to that of a human renal dipeptidase. The dipeptidase successfully synthesized the precursor of the dipeptide sweetener Z-l-Asp-d-AlaOBzl.


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