MAM33/YIL070C Summary Help

Standard Name MAM33 1
Systematic Name YIL070C
Feature Type ORF, Verified
Description Acidic protein of the mitochondrial matrix; involved in oxidative phosphorylation; related to the human complement receptor gC1q-R (1, 2 and see Summary Paragraph)
Name Description Mitochondrial Acidic Matrix protein 1
Chromosomal Location
ChrIX:231072 to 230272 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All MAM33 GO evidence and references
  View Computational GO annotations for MAM33
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 1 genes
Classical genetics
Large-scale survey
109 total interaction(s) for 96 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 86
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 1
  • Biochemical Activity: 6
  • Co-crystal Structure: 1
  • Co-fractionation: 1
  • PCA: 6
  • Protein-peptide: 2
  • Reconstituted Complex: 2

Genetic Interactions
  • Synthetic Lethality: 1

Expression Summary
Length (a.a.) 266
Molecular Weight (Da) 30,132
Isoelectric Point (pI) 4.34
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIX:231072 to 230272 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1994-12-10
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..801 231072..230272 2011-02-03 1994-12-10
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000001332

MAM33 encodes an acidic protein of unknown function that is localized to the mitochondrial matrix (2, 1). Mam33p (previously termed p30, 2) is highly conserved, with putative homologs in mammals, C. elegans, A. nidulans, and Trypanosoma brucei (2, 1, 3, 4). When expressed in S. cerevisiae, the human homolog C1QBP complements the observed slow respiratory growth phenotype of the mam33 null mutant (2). Human C1QBP binds to many different proteins, but its cellular role is unclear (see 2). The T. brucei putative Mam33p homolog, p22, binds to and regulates the RNA-binding activity of a protein that binds to guide RNAs during the mitochondrial RNA editing process (4).

The N-terminal 47 residues of Mam33p are removed upon import into mitochondria (1), and it is found in the mitochondrial matrix as a multimer, probably a homotrimer or homotetramer (1). Mam33p binds to a segment of Cyb2p (cytochrome b2) that is responsible for sorting Cyb2p to the mitochondrial intermembrane space, but the significance of this is unclear since the mam33 null mutation does not affect mitochondrial import or sorting (1). There are conflicting reports on the phenotype of the mam33 null mutant: one report describes a reduced respiratory growth phenotype on a glycerol carbon source (2), while another report describes wild-type growth on glycerol but a growth defect on minimal medium with lactate as sole carbon source (1).

Last updated: 2005-07-01 Contact SGD

References cited on this page View Complete Literature Guide for MAM33
1) Seytter T, et al.  (1998) Mam33p, an oligomeric, acidic protein in the mitochondrial matrix of Saccharomyces cerevisiae is related to the human complement receptor gC1q-R. Yeast 14(4):303-10
2) Muta T, et al.  (1997) p32 protein, a splicing factor 2-associated protein, is localized in mitochondrial matrix and is functionally important in maintaining oxidative phosphorylation. J Biol Chem 272(39):24363-70
3) Van Den Brulle J, et al.  (1999) Cloning and characterization of an Aspergillus nidulans gene involved in the regulation of penicillin biosynthesis. Appl Environ Microbiol 65(12):5222-8
4) Hayman ML, et al.  (2001) The trypanosome homolog of human p32 interacts with RBP16 and stimulates its gRNA binding activity. Nucleic Acids Res 29(24):5216-25