Two Nearly Identical Aromatic Compound Hydrolase Genes in a Strong Polychlorinated Biphenyl Degrader,Rhodococcus sp. Strain RHA1

1998 ◽  
Vol 64 (6) ◽  
pp. 2006-2012 ◽  
Author(s):  
Akihiro Yamada ◽  
Hidekazu Kishi ◽  
Katsumi Sugiyama ◽  
Takashi Hatta ◽  
Kanji Nakamura ◽  
...  

ABSTRACT The two 2-hydroxy-6-oxohepta-2,4-dienoate (HOHD) hydrolase genes,etbD1 and etbD2, were cloned from a strong polychlorinated biphenyl (PCB) degrader, Rhodococcus sp. strain RHA1, and their nucleotide sequences were determined. TheetbD2 gene was located in the vicinity of bphAgene homologs and encoded an enzyme whose amino-terminal sequence was very similar to the amino-terminal sequence of the HOHD hydrolase which was purified from RHA1. Using the etbD2 gene fragment as a probe, we cloned the etbD1 gene encoding the purified HOHD hydrolase by colony hybridization. Both genes encode a product having 274 amino acid residues and containing the nucleophile motif conserved in α/β hydrolase fold enzymes. The deduced amino acid sequences were quite similar to the amino acid sequences of the products of the single-ring aromatic hydrolase genes, such as dmpD,cumD, todF, and xylF, and not very similar to the amino acid sequences of the products of bphDgenes from PCB degraders, including RHA1. The two HOHD hydrolase genes and the RHA1 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate (HPDA) hydrolase gene, bphD, were expressed in Escherichia coli, and their relative enzymatic activities were examined. The product ofbphD was very specific to HPDA, and the products ofetbD1 and etbD2 were specific to HOHD. All of the gene products exhibited poor activities against themeta-cleavage product of catechol. These results agreed with the results obtained for BphD and EtbD1 hydrolases purified from RHA1. The three hydrolase genes exhibited similar induction patterns both in an RNA slot blot hybridization analysis and in a reporter gene assay when a promoter probe vector was used. They were induced by biphenyl, ethylbenzene, benzene, toluene, and ortho-xylene. Strain RCD1, an RHA1 mutant strain lacking both the bphDgene and the etbD2 gene, grew well on ethylbenzene. This result suggested that the etbD1 gene product is involved in the meta-cleavage metabolic pathway of ethylbenzene.

2001 ◽  
Vol 47 (12) ◽  
pp. 1075-1081 ◽  
Author(s):  
Kimitoshi Denda ◽  
Akira Oshima ◽  
Yoshihiro Fukumori

Cytochrome aco3 from a facultatively alkalophilic bacterium, Bacillus YN-2000, was found to be alkaline- and heat-tolerant. To better understand the structural features of Bacillus YN-2000 cytochrome aco3, the gene encoding this enzyme was cloned and sequenced. Nucleotide sequence analyses of the region neighboring the acoI (subunit I) gene revealed that the acoII (subunit II) and acoIII (subunit III) genes were concomitantly clustered upstream and downstream of the acoI gene, respectively, forming an operon with transcriptional polarity. The deduced amino acid sequence of subunit I was highly similar to that of cytochrome caa3 from thermophilic bacterium Bacillus PS3 in which the heme a3 could be replaced with heme o. Furthermore, a marked paucity of basic amino acid residues was found in the cytochrome c-binding subunit II, which might be a result of the adaptation to a highly alkaline external milieu.Key words: cytochrome c oxidase, alkalophile, thermostability, heme o, Bacilli.


1987 ◽  
Author(s):  
Patricia DePoli ◽  
Theresa Bacon-Baquley ◽  
Daniel A Walz

Platelet thrombospondin (TSP) interacts with plasminogen in a specific and saturable manner. TSP can form a trimolecular complex with histidine-rich glycoprotein and plasminogen and the plasminogen within such complexes can reportedly be activated by tissue plasminogen activator. We have studied the interaction of TSP with plasminogen using Western blotting of plasminogen, reduced plasmin and the elastase-generated fragments of plasminogen and their binding of iodinated TSP. TSP was found to specifically bind to plasminogen and the heavy (non-enzyme) chain of plasmin in a calcium-independent manner. Binding could be blocked by preincubation of the immobilized plasminogen or plasmin with an excess of unlabeled TSP. Plasminogen domains (kringles) were generated by limited eTastase proteolysis. TSP bound specifically to a single 51 kDa plasminogen fragment. The elastase-generated fragments were separated by lysine-Sepharose chromatography and their identities established by amino acid composition and amino-terminal sequence analysis. The 51 kDa plasminogen fragment bound to lysine-Sepharose and had an amino-terminal sequence corresponding to kringle 4 (K4) and a composition consistent with that of K4-K5-plasmin. TSP binding to this fragment was not blocked by the presence of an excess of the fragment K1-K2-K3, K4, nor miniplasminogen (K5-plasmin). Binding does not appear to be directly dependent upon the specific high-affinity lysine binding site of the 51 kDa fragment. Our data suggests that thrombospondin interacts with plasminogen at a single distinct site, and that this recognition site is at or near the K4-K5 contiguous region of plasminogen.


1989 ◽  
Vol 39 (3) ◽  
pp. 315-325 ◽  
Author(s):  
Johannes J. Volwerk ◽  
Peter B. Wetherwax ◽  
Loreene M. Evans ◽  
Andreas Kuppe ◽  
O. Hayes Griffith

1981 ◽  
Vol 154 (3) ◽  
pp. 989-993 ◽  
Author(s):  
M Pras ◽  
E C Franklin ◽  
F Prelli ◽  
B Frangione

Amyloid fibrils were isolated from spleen and thyroid obtained at autopsy from one patient (S.K.O.) of Jewish origin with familial amyloidotic polyneuropathy. Gel filtration on Sephadex G100 after solubilization in 5 M guanidine HCl yielded three major components with 14,000, 9,000, and 5,000 mol wt, respectively. The two larger components shared antigenic determinants with human prealbumin. Amino acid analysis and amino terminal sequence studies revealed the 14,000-mol wt protein to be an intact prealbumin subunit. The 9,000-mol wt fragment obtained in highest yield encompassed the region from position 49-127 and the 5,000 mol wt fraction encompassed the amino terminal of prealbumin (position 1-48). An amino acid substitution (Gly/Thr) was detected at position 49, where enzymatic cleavage occurred. Thus, several prealbumin-derived fragments, predominantly the carboxyl end, constitute the amyloid fibrils in a heredofamilial amyloidosis syndrome of dominant inheritance.


Parasitology ◽  
1991 ◽  
Vol 103 (3) ◽  
pp. 387-394 ◽  
Author(s):  
G. Bardehle ◽  
F. J. Conraths ◽  
F. Fahrenholz ◽  
M. Hintz ◽  
D. Linder ◽  
...  

The major glycoprotein of the sheath of Litomosoides carinii microfilariae (gp22) was analysed for its amino acid and amino sugar composition. It is rich in proline, glutamine/glutamic acid and glycine and contains (N-acetyl)galactosamine. The N-terminal amino acid sequence was determined up to position 37. It consists of a group of 6 repeats of the pentapeptide sequence methionine-glycine-proline-glutamine-proline with two minor modifications in repeats 3–6, while the first two repeats follow the general pattern more loosely. Identical N-terminal amino acid sequences were found in at least two other sheath polypeptides (33 kDa, 39 kDa). Antisera prepared against 3 overlapping synthetic peptides corresponding to the amino terminus of gp22 recognized different epitopes. They all reacted with identical patterns of sheath polypeptides. The antisera failed to recognize antigens of 4th-stage larvae of L. carinii. In contrast, cross-reacting epitopes were detected in other parasite stages. Antisera reacted with material surrounding embryos and microfilariae in the uterus of females, and caused patchy fluorescence on the sheath of blood-derived and in vitro-released microfilariae.


1979 ◽  
Vol 91 (3) ◽  
pp. 449-461 ◽  
Author(s):  
Lisbeth Myhre ◽  
Kaare M. Gautvik

ABSTRACT Two antisera with known region specificities have been used to characterize calcitonin immunoreactivity (iCT) in serum of patients with medullary thyroid carcinoma (MCT). Antiserum I which was raised against the synthetic hormone (1–32 amino acid residues), contained heterogeneous populations of immunoglobulins directed predominantly against carboxyterminal sequences of the hormone, but the antiserum reacted also with the amino-terminal fragment (1–10 amino acid residues). Antiserum II, which was raised against the carboxy-terminal hormone fragment (11–32 amino acid residues) reached equally well with the intact hormone and the C-terminal fragment, but showed negligible binding of the amino terminal fragment. Antiserum I measured therefore both amino-terminal and carboxy-terminal sequences of calcitonin while antiserum II measured only carboxy-terminal amino acid sequences. In 40 patients with MCT, antiserum I measured usually the highest concentration of serum iCT suggesting the presence of non-uniform hormone immunoreactivity. The different molecular forms of circulating iCT in 7 MCT patients were explored by using antiserum I after gel filtration on Sephadex G-100. The patients who were selected on basis of iCT measurement in serum using antiserum I and II, could be divided into 3 groups which showed characteristic iCT profiles. Group 1, in which antiserum II measured a higher concentration of serum iCT, contained predominantly (60–70 %) small fragments of calcitonin immunoreactivity. On the other hand, in the sera of group 3 in which antisera I measured an equal or the highest concentrations, the dominant form of the hormone consisted of molecular sequences equal to or larger than the intact hormone (90 %). In group 2, the two antisera measured an equal amount of serum iCT and molecular forms consisting mostly of larger hormone fragments dominated (50 %). All the patients were normocalcaemic in spite of frequently grossly elevated serum iCT, and 33 out of 36 patients had normal serum immunoreactive parathyroid hormone. In conclusion: 1. Serum iCT is heterogeneous and represents peptides of quite different molecular size with no or low biological activity. 2. Most of the serum calcitonin immunoreactivity consists of peptides with carboxy-terminal amino acid sequences. 3. Most, if not all, of the amino-terminal calcitonin immunoreactivity is due to monomeric and polymeric hormonal forms.


1969 ◽  
Vol 22 (2) ◽  
pp. 471 ◽  
Author(s):  
IJ O'donnell

Component 8 is a major component extracted from reduced and carboxy-methylated wool. Further study of its reaction with cyanogen bromide and of the fractions obtained under carefully controlled disaggregating conditions has rev<\laled that while most of the methionine residues are in the same position relative to the ends of the chains, at least 30% of them appear to be in a different chemical environment from the rest. The evidence can be interpreted in terms of variations in some of the amino acids at particular points in a fundamental sequence of the 60 residues (CNBr3) at the amino terminal end. Further amino acid sequences near the acetylated terminal residue have been determined and provide examples of the amino acid variatioIl along the chain. One sequeIlce with variants is: N-acetyISer-(Tyr or Phe Or Pro)-Asp-(Phe or Leu)-SCMCySH-Leu-Pro-Asp-Leu-Ser-Phe-Arg-. There is a region in component 8 where many of the S-carboxymethylcysteine residues are congregated.


2010 ◽  
Vol 76 (19) ◽  
pp. 6423-6430 ◽  
Author(s):  
José M. Viader-Salvadó ◽  
Juan A. Gallegos-López ◽  
J. Gerardo Carreón-Treviño ◽  
Miguel Castillo-Galván ◽  
Arturo Rojo-Domínguez ◽  
...  

ABSTRACT Thermostable phytases, which are active over broad pH ranges, may be useful as feed additives, since they can resist the temperatures used in the feed-pelleting process. We designed new beta-propeller phytases, using a structure-guided consensus approach, from a set of amino acid sequences from Bacillus phytases and engineered Pichia pastoris strains to overproduce the enzymes. The recombinant phytases were N-glycosylated, had the correct amino-terminal sequence, showed activity over a pH range of 2.5 to 9, showed a high residual activity after 10 min of heat treatment at 80°C and pH 5.5 or 7.5, and were more thermostable at pH 7.5 than a recombinant form of phytase C from Bacillus subtilis (GenBank accession no. AAC31775). A structural analysis suggested that the higher thermostability may be due to a larger number of hydrogen bonds and to the presence of P257 in a surface loop. In addition, D336 likely plays an important role in the thermostability of the phytases at pH 7.5. The recombinant phytases showed higher thermostability at pH 5.5 than at pH 7.5. This difference was likely due to a different protein total charge at pH 5.5 from that at pH 7.5. The recombinant beta-propeller phytases described here may have potential as feed additives and in the pretreatment of vegetable flours used as ingredients in animal diets.


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