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G Cullmann

Publications and source records attributed to G Cullmann.

8 recordsLinked to original sources
PubMed1995

Characterization of the five replication factor C genes of Saccharomyces cerevisiae.

Replication factor C (RFC) is a five-subunit DNA polymerase accessory protein that functions as a structure-specific, DNA-dependent ATPase. The ATPase function of RFC is activated by proliferating cell nuclear antigen. RFC was originally purified from human cells on the basis of its requirement for simian virus 40 DNA replication in vitro. A functionally homologous protein complex from Saccharomyces cerevisiae, called ScRFC, has been identified. Here we report the cloning, by either peptide sequencing or by sequence similarity to the human cDNAs, of the S. cerevisiae genes RFC1, RFC2, RFC3, RFC4, and RFC5. The amino acid sequences are highly similar to the sequences of the homologous human RFC 140-, 37-, 36-, 40-, and 38-kDa subunits, respectively, and also show amino acid sequence similarity to functionally homologous proteins from Escherichia coli and the phage T4 replication apparatus. All five subunits show conserved regions characteristic of ATP/GTP-binding proteins and also have a significant degree of similarity among each other. We have identified eight segments of conserved amino acid sequences that define a family of related proteins. Despite their high degree of sequence similarity, all five RFC genes are essential for cell proliferation in S. cerevisiae. RFC1 is identical to CDC44, a gene identified as a cell division cycle gene encoding a protein involved in DNA metabolism. CDC44/RFC1 is known to interact genetically with the gene encoding proliferating cell nuclear antigen, confirming previous biochemical evidence of their functional interaction in DNA replication.

Amino Acid Sequence↗
PubMed1993

Cloning of a mouse cDNA encoding DNA polymerase delta: refinement of the homology boxes.

A mouse DNA polymerase delta (Pol delta)-encoding cDNA (pol delta) was isolated by PCR amplification and cDNA library screening. The sequenced cDNA has a length of 3386 bp and the open reading frame (ORF) encodes a protein of 1105 amino acids (aa) with an M(r) of 123,743. The aa identity to the proteins encoded by the corresponding cDNA from Bos taurus (93%) and Homo sapiens (92%) is very high. The identity to the Pol delta from Schizosaccharomyces pombe, Saccharomyces cerevisiae and Plasmodium falciparum is around 50%. An aa comparison between all available Pol delta sequences reveals several common structural motifs. Polyclonal antibodies raised against a 31-aa synthetic peptide deduced from the ORF specifically recognize Pol delta polymerases from human cells and calf thymus in an immunoblot.

Amino Acid Sequence↗
PubMed1991

The Q300 gene: a novel transcription unit induced in simian virus 40-infected and -transformed mouse cells.

The Q300 element is a single-copy 233-bp genomic mouse DNA fragment carrying a high-affinity binding site for the simian virus 40 (SV40) large T antigen. This element was used to screen an EMBL3 mouse genomic library. We could identify a genomic clone containing an approximately 500-bp transcribed region flanking the Q300 element. The transcribed region, termed the Q300 transcription unit or Q300 gene, is overexpressed in acutely SV40-infected or SV40-transformed mouse and rat cells. The Q300 gene includes an open reading frame which has the coding potential for a small polypeptide with an extremely hydrophobic N terminus and a hydrophilic C terminus. The deduced polypeptide has some similarity with the papillomavirus E5 oncoprotein.

Amino Acid Sequence↗
PubMed1984

The mathematical logic of life.

Protein synthesis can be likened to a particular coded information storage, transmission and execution system. Noise, error or mutations are the essential phenomena to which a living organism is subjected. Genetic coding aims at preserving the integrity of a structure under aggression from the surroundings. It can be shown that the different amino acids translated in the proteins, except the particular case of SER, obey a logical code for optimization of resistance to mutation effects. The study of the structure of this code allows a better comprehension of the logic of life.

Escherichia coli↗
PubMed1983

Noise immunity of the genetic code.

Error detection and correction properties are fundamental for informative codes. Hamming's distance allows us to study this noise resistance. We present codes characterized by the resistance optimization to nonsense mutational effects. The calculation of the cumulated Hamming's distance allowing to determine the number of optimal codes and their structure can be detailed. The principle of these laws of optimization of resistance consists of choosing constituent codons connected by mutational neighbouring in such a way that random application of mutations on such a code minimize the occurrence of nonsense n-uplets or terminators. New coding symmetries are then described and screened using Galois's polynomials properties and Baudot's code. Such a study can be applied to any length of the codons. Here we present the principles of this optimization for the most simple doublet codes. Another constraint is discussed: the distribution of optimal subcodes for synonymity and the frequencies of utilization of the different codons. We compare these results to those of the present genetic code, and we observe that all coded amino acids (except the particular case of SER) are using optimal sub-codes of synonymity. This work suggests that the appearance of the genetic code was provoked by mutations while optimizing on several levels its resistance to their effects. Thus genetic coding would have been the best automata that could be produced in prebiotic conditions.

Base Sequence↗
PubMed1983

[Baudot's code, weft of the genetic code].

Enumerating Bn numbers using only Bn figures is possible thanks to an overlapping reading of a cyclic sequence built according to Baudot's code. This code allows the genetic code to be screened to show the distribution of the synonyms of the aminoacids. The assignments of the genetic code obey strict laws of optimisation of resistance against the effects of mutations.

Amino Acid Sequence↗