Biomedical subjects

E Ollivier

Publications and source records attributed to E Ollivier.

3 recordsLinked to original sources

PubMed1992

Higher eucaryotic cdc25 proteins are structurally related to phosphoseryl/threonyl protein phosphatases.

cdc25 proteins are universally involved in the control of cell division. Using an original method of sequence analysis, cdc25 proteins from different sources were compared to protein phosphatases. Protein phosphatases could clearly be characterized as two distinct protein families, the phospho-seryl/threonyl phosphatases, and the phospho-tyrosyl phosphatases. None of the cdc25 proteins analyzed fitted with the phospho-tyrosyl phosphatases, indicating that if they indeed possess this biochemical activity, they form a distinct phsophatase protein group. Unexpectedly, higher eucaryotic cdc25 proteins (from human and fly) were found to be structurally related to phospho-seryl/threonyl phosphatases. These results fit well with expected function of the proteins, associated solely in higher eucaryotes, to dephosphorylation of threonine in the cell cycle control protein cdc2.

Animals↗

PubMed1991

'Multifrequency' location and clustering of sequence patterns from proteins.

In previous work, we have shown that a set of characteristics, defined as (code frequency) pairs, can be derived from a protein family by the use of a signal-processing method. This method enables the location and extraction of sequence patterns by taking into account each (code frequency) pair individually. In the present paper, we propose to extend this method in order to detect and visualize patterns by taking into account several pairs simultaneously. Two 'multifrequency' methods are described. The first one is based on a rewriting of the sequences with new symbols which summarize the frequency information. The second method is based on a clustering of the patterns associated with each pair. Both methods lead to the definition of significant consensus sequences. Some results obtained with calcium-binding proteins and serine proteases are also discussed.

Amino Acid Sequence↗

PubMed1990

A scale-independent signal processing method for sequence analysis.

In this paper, we present methods to detect and localize patterns in biologically related protein sequences (family). The patterns common to the sequences of the family are detected by using Fourier analysis. No previous scales (codes) are needed, they are actually produced as a result of the analysis procedure, together with the frequencies of the Fourier decompositions. Characteristic features of the family are thus expressed as (code-frequency) pairs. Various tools are proposed in order to localize the patterns, to compare the codes, and to evaluate the proximity of an arbitrary sequence to the investigated family. The general strategy is illustrated on a family composed of calcium-binding proteins.

Amino Acid Sequence↗