Identification of critical amino acid residues of Saccharomyces cerevisiae carbamoyl-phosphate synthetase: definition of the ATP site involved in carboxy-phosphate formation

alpha-Agglutinin is a cell adhesion glycoprotein expressed on the cell wall of Saccharomyces cerevisiae alpha cells. Binding of alpha-agglutinin to its ligand a-agglutinin, expressed by a cells, mediates cell-cell contact during mating. Analysis of truncations of the 650-amino-acid alpha-agglutinin structural gene AG alpha 1 delineated functional domains of alpha-agglutinin. Removal of the C-terminal hydrophobic sequence allowed efficient secretion of the protein and loss of cell surface attachment. This cell surface anchorage domain was necessary for linkage to a glycosyl phosphatidylinositol anchor. A construct expressing the N-terminal 350 amino acid residues retained full a-agglutinin-binding activity, localizing the binding domain to the N-terminal portion of alpha-agglutinin. A 278-residue N-terminal peptide was inactive; therefore, the binding domain includes residues between 278 and 350. The segment of alpha-agglutinin between amino acid residues 217 and 308 showed significant structural and sequence similarity to a consensus sequence for immunoglobulin superfamily variable-type domains. The similarity of the alpha-agglutinin-binding domain to mammalian cell adhesion proteins suggests that this structure is a highly conserved feature of adhesion proteins in diverse eukaryotes.

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Direct demonstration of critical amino acid residues required for cytotoxic T-lymphocyte allorecognition of H-2 class I antigens.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.85.9.3085 ◽

1988 ◽

Vol 85 (9) ◽

pp. 3085-3089 ◽

Cited By ~ 6

Author(s):

E. McLaughlin-Taylor ◽

C. G. Miyada ◽

M. McMillan ◽

R. B. Wallace

Keyword(s):

Amino Acid ◽

T Lymphocyte ◽

Cytotoxic T Lymphocyte ◽

Class I ◽

Amino Acid Residues ◽

Critical Amino Acid ◽

Direct Demonstration

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Definition of Essential Amino Acid Residues in the Recognition of a Peptide by a Mouse Monoclonal Antibody

Zeitschrift für Naturforschung C ◽

10.1515/znc-1997-3-423 ◽

1997 ◽

Vol 52 (3-4) ◽

pp. 274-278

Author(s):

Laura Rosanó ◽

Francesca Di Modugno ◽

Giulia Romagnoli ◽

Alberto Chersi

Keyword(s):

Monoclonal Antibody ◽

Amino Acid ◽

Critical Role ◽

Binding Activity ◽

Mouse Monoclonal Antibody ◽

Amino Acid Residues ◽

Binding Data ◽

Amino Acid Stretch ◽

Definition Of ◽

Key Residues

AbstractA mouse monoclonal antibody reacting in ELISA with a synthetic peptide representing a linear amino acid stretch of the protein antigen was tested on all overlap ping 5-mer to 9-mer fragments of the peptide, as prepared by multi-pin synthesis. Analysis of the binding data suggests that several residues in the peptide might be relatively unrelevant for recognition, while few others seem to play a critical role as key residues. On the basis of such observations, we attempted to reconstruct an alternative essential epitope by introducing multiple amino acid substitutions in the 9-mer peptide exhibiting the best binding activity, and then tested its ability to be recognized by the monoclonal antibody.

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Role of Integrase in Reverse Transcription of the Saccharomyces cerevisiae Retrotransposon Ty1

Eukaryotic Cell ◽

10.1128/ec.4.6.1057-1065.2005 ◽

2005 ◽

Vol 4 (6) ◽

pp. 1057-1065 ◽

Cited By ~ 14

Author(s):

M. Wilhelm ◽

F.-X. Wilhelm

Keyword(s):

Saccharomyces Cerevisiae ◽

Amino Acid ◽

Specific Activity ◽

Rnase H ◽

Amino Acid Residues ◽

Acidic Amino Acid ◽

Acidic Domain ◽

Basic Region

ABSTRACT Reverse transcriptase (RT) with its associated RNase H (RH) domain and integrase (IN) are key enzymes encoded by retroviruses and retrotransposons. Several studies have implied a functional role of the interaction between IN and RT during the replication of retroviral and retrotransposon genomes. In this study, IN deletion mutants were used to investigate the role of IN on the RT activity of the yeast Saccharomyces cerevisiae retrotransposon Ty1. We have identified two domains of Ty1 integrase which have effects on RT activity in vivo. The deletion of a domain spanning amino acid residues 233 to 520 of IN increases the exogenous specific activity of RT up to 20-fold, whereas the removal of a region rich in acidic amino acid residues between residues 521 and 607 decreases its activity. The last result complements our observation that an active recombinant RT protein can be obtained if a small acidic tail mimicking the acidic domain of IN is fused to the RT-RH domain. We suggest that interaction between these acidic amino acid residues of IN and a basic region of RT could be critical for the correct folding of RT and for the formation of an active conformation of the enzyme.

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