Amino acid substitutions in the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase that influence catalytic activity of the holoenzyme

Biochemistry ◽  
1992 ◽  
Vol 31 (2) ◽  
pp. 519-525 ◽  
Author(s):  
Betsy A. Read ◽  
F. Robert Tabita
Keyword(s):  
Catalytic Activity ◽  
Amino Acid ◽  
Small Subunit ◽  
Amino Acid Substitutions ◽  
Bisphosphate Carboxylase

The Study of Plant Phylogeny Using Amino-Acid-Sequences of Ribulose-1,5-Bisphosphate Carboxylase .VI. Some Solanum and Allied Species From Different Continents

1986 ◽  
Vol 34 (2) ◽  
pp. 187 ◽  
Author(s):  
PG Martin ◽  
JM Dowd ◽  
C Morris ◽  
DE Symon
Keyword(s):  
Amino Acid ◽  
Continental Drift ◽  
Small Subunit ◽  
Amino Acid Sequences ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Plant Phylogeny ◽  
Molecular Evolutionary Clock ◽  
Evolutionary Clock

The N-terminal 40 amino acid sequences of the small subunit of ribulose bisphosphate carboxylase have been determined for 13 species of Solanum, one other species of Solanaceae and two of Convolvulaceae. From these, and previously published sequences from Solanaceae, a minimal phylogenetic tree is derived. This agrees well with current taxonomy; the first dichotomy in the Solanaceae tree is between the two subfamilies Solanoideae and Cestroideae; within Solanum the subgenera Solanum and Leptostemonum separate dichotomously; within subgenus Leptostemonum the African and Asian species diverge from the Australian. Within the Australian species of subgenus Leptostemonum two most unusual substitutions have been noted. The implications for the hypotheses of a 'molecular evolutionary clock' and of biogeographical dispersal by continental drift are discussed.

The study of plant phylogeny using amino acid sequences of Ribulose-1,5-Bisphosphate Carboxylase. V. Magnoliaceae, Polygonaceae and the concept of primitiveness

1984 ◽  
Vol 32 (3) ◽  
pp. 301 ◽  
Author(s):  
PG Martin ◽  
JM Dowd
Keyword(s):  
Amino Acid ◽  
Cytochrome C ◽  
Phylogenetic Tree ◽  
Small Subunit ◽  
Amino Acid Sequences ◽  
Family Tree ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Plant Phylogeny

N-terminal, 40 amino acid sequences of ribulose bisphosphate carboxylase small subunit are given for three species of Polygonaceae, three of Magnoliaceae and for Metasequoia. Making use of three plastocyanin and one cytochrome c sequences from the literature, these families are added to a previously published phylogenetic tree. Fagaceae and Proteaceae are also added. Uncertainties in the 14-family tree are pointed out. The root of the tree is identified using gymnosperm sequences. The concept of primitiveness as it is relevant to this research is discussed. From the phylogenetic tree there is no evidence for primitiveness of Magnoliaceae, though it is not precluded. Polygonaceae and Chenopodiaceae form a branch that diverges from the main tree near the presumptive dicotyledonous origin.

scholarly journals Prediction of the Evolution of Ceftazidime Resistance in Extended-Spectrum β-Lactamase CTX-M-9

2006 ◽  
Vol 50 (2) ◽  
pp. 731-738 ◽  
Author(s):  
J. Delmas ◽  
F. Robin ◽  
F. Carvalho ◽  
C. Mongaret ◽  
R. Bonnet
Keyword(s):  
Catalytic Activity ◽  
Amino Acid ◽  
Active Site ◽  
Random Mutagenesis ◽  
Evolutionary Process ◽  
Catalytic Efficiency ◽  
Kinetic Constants ◽  
The Other ◽  
Amino Acid Substitutions ◽  
Evolutionary Potential

ABSTRACT A random mutagenesis technique was used to predict the evolutionary potential of β-lactamase CTX-M-9 toward the acquisition of improved catalytic activity against ceftazidime. Thirty CTX-M mutants were obtained during three rounds of mutagenesis. These mutants conferred 1- to 128-fold-higher MICs of ceftazidime than the parental enzyme CTX-M-9. The CTX-M mutants contained one to six amino acid substitutions. Mutants harbored the substitutions Asp240Gly and Pro167Ser, which were previously observed in clinical CTX-M enzymes. Additional substitutions, notably Arg164His, Asp179Gly, and Arg276Ser, were observed near the active site. The kinetic constants of the three most active mutants revealed two distinct ways of improving catalytic efficiency against ceftazidime. One enzyme had a 17-fold-higher k cat value than CTX-M-9 against ceftazidime. The other two had 75- to 300-fold-lower Km values than CTX-M-9 against ceftazidime. The current emergence of CTX-M β-lactamases with improved activity against ceftazidime may therefore be the beginning of an evolutionary process which might subsequently generate a great diversity of CTX-M-type ceftazidimases.

Molecular evolutionary analyses of the small and large subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase

1992 ◽  
Vol 70 (4) ◽  
pp. 715-723 ◽  
Author(s):  
J. J. Pasternak ◽  
B. R. Glick
Keyword(s):  
Amino Acid ◽  
Molecular Evolution ◽  
Large Subunit ◽  
Distance Matrix ◽  
Small Subunit ◽  
Amino Acid Sequences ◽  
Sequence Information ◽  
Bisphosphate Carboxylase ◽  
Tree Building ◽  
Building Methods

The molecular evolution of the amino acid sequences of the mature small and large subunits of ribulose-1,5-bisphosphate carboxylase/oxygense (Rubisco) was determined. The dataset for each subunit consisted of sequences from 39 different taxa of which 22 are represented with sequence information for both subunits. Phylogenetic trees were reconstructed using distance matrix, parsimony and simultaneous alignment and phylogeny methods. For the small subunit, the latter two methods produced similar trees that differed from the topology of the distance matrix tree. For the large subunit, each of the three tree-building methods yielded a distinct tree. Except for the distance matrix small subunit tree, the tree-building methods produced topologies for the small and large subunit sequences from the nonflowering plant taxa that, for the most part, agree with current taxonomic schemes. With the full datasets, the lack of consistency both among the various trees and with conventional taxonomic relationships was most evident with the Rubisco sequences from angiosperms. It is unlikely that current tree-building methods will be able to reconstruct an unambiguous molecular evolution of either of the Rubisco subunits. Molecular trees, regardless of methodology, showed similar topologies for the small and large subunits from the 22 taxa from which both subunits have been sequenced, indicating that the subunits have changed to the same extent over time. In this case, similar trees were formed because only 4 of the 22 taxa were from dicots. Key words: ribulose-1,5-bisphosphate carboxylase/oxygenase, amino acid sequence, molecular evolution, phyletic trees.

Sign in / Sign up

Export Citation Format

Share Document