MRPS21

Protein identityUniProt · HPA

UniProt accession

P82921

Gene

MRPS21

Ensembl

ENSG00000266472

Chromosome

1

Canonical length

87 aa

Protein class

Predicted intracellular proteins, Ribosomal proteins

Subcellular location

Mitochondria

OverviewNCBI Gene

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 28S subunit protein that belongs to the ribosomal protein S21P family. Pseudogenes corresponding to this gene are found on chromosomes 1p, 1q, 9p, 10p, 10q, 16q, and 17q. Available sequence data analyses identified splice variants that differ in the 5' UTR; both transcripts encode the same protein. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

87 residues, UniProt reviewed canonical sequence.

>P82921|MRPS21
     1  MAKHLKFIAR TVMVQEGNVE SAYRTLNRIL TMDGLIEDIK HRRYYEKPCC RRQRESYERC
    61  RRIYNMEMAR KINFLMRKNR ADPWQGC

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MRPS21 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability

Intracellular

Secreted

No

Transmembrane segments

0

Mean surface accessibility (rSASA)

0.51

Highest tissue expression

145 nTPM

Expression across tissuesHPA

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)

1.56

gnomAD pLI

0.06

gnomAD missense Z

0.4

DepMap mean gene effect

-0.93

DepMap dependency class

common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 20% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

• mitochondrial translation
• translation

Molecular functions

• RNA binding
• structural constituent of ribosome

Cellular components

• mitochondrial inner membrane
• mitochondrial small ribosomal subunit
• mitochondrion

Protein domainsUniProt · Pfam · InterPro

• Small ribosomal subunit protein bS21
• Small ribosomal subunit protein bS21 superfamily
• Ribosomal protein S21

KeywordsUniProt

• Mitochondrion
• Ribonucleoprotein
• Ribosomal protein

InteractionsUniProt · HPA

Protein binding partners of MRPS21 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• AURKAIP1
• MRPS9