Rv3876 (espI)
Current annotations:
TBCAP: (community-based annotations - see table at bottom of page )
TBDB: hypothetical protein
REFSEQ: hypothetical protein
PATRIC: RD1 region associated protein Rv3876
TUBERCULIST: ESX-1 secretion-associated protein EspI. Conserved proline and alanine rich protein.
NCBI: ESX-1 secretion-associated protein EspI Conserved proline and alanine rich protein
updated information (H37Rv4):
gene name: espI
function:
reference:
Coordinates in H37Rv: 4353010 - 4355010
Gene length: 2001 bp (with stop codon), 666 aa (without stop codon)
Operon:
Trans-membrane region:
Role: V - Conserved hypotheticals
GO terms:
Reaction(s) (based on iSM810 metabolic model):
Gene Expression Profile Gene Modules Orthologs among selected mycobacteria Protein structure:
Search for Latest Homologs in PDB Top 10 Homologs in PDB (as of Apr 2026): (none with >35% aa id)
Links to additional information on espI:
Amino Acid Sequence
MAADYDKLFRPHEGMEAPDDMAAQPFFDPSASFPPAPASANLPKPNGQTPPPTSDDLSERFVSAPPPPPPPPPPPPPTPMPIAAGEPPSPEPAASKPPTP
PMPIAGPEPAPPKPPTPPMPIAGPEPAPPKPPTPPMPIAGPAPTPTESQLAPPRPPTPQTPTGAPQQPESPAPHVPSHGPHQPRRTAPAPPWAKMPIGEP
PPAPSRPSASPAEPPTRPAPQHSRRARRGHRYRTDTERNVGKVATGPSIQARLRAEEASGAQLAPGTEPSPAPLGQPRSYLAPPTRPAPTEPPPSPSPQR
NSGRRAERRVHPDLAAQHAAAQPDSITAATTGGRRRKRAAPDLDATQKSLRPAAKGPKVKKVKPQKPKATKPPKVVSQRGWRHWVHALTRINLGLSPDEK
YELDLHARVRRNPRGSYQIAVVGLKGGAGKTTLTAALGSTLAQVRADRILALDADPGAGNLADRVGRQSGATIADVLAEKELSHYNDIRAHTSVNAVNLE
VLPAPEYSSAQRALSDADWHFIADPASRFYNLVLADCGAGFFDPLTRGVLSTVSGVVVVASVSIDGAQQASVALDWLRNNGYQDLASRACVVINHIMPGE
PNVAVKDLVRHFEQQVQPGRVVVMPWDRHIAAGTEISLDLLDPIYKRKVLELAAALSDDFERAGRR
(
Nucleotide sequence available on
KEGG )
Additional Information
MtbTnDB - interactive tool for exploring a database of published TnSeq datasets for Mtb
TnSeqCorr
Rv3876/espI,
gene len: 2000 bp, num TA sites: 25
condition dataset call medium method notes
in-vitro DeJesus 2017 mBio non-essential 7H9 HMM fully saturated, 14 TnSeq libraries combined
in-vitro Sassetti 2003 Mol Micro no data 7H9 TRASH essential if hybridization ratio<0.2
in-vivo (mice) Sassetti 2003 PNAS essential BL6 mice TRASH essential if hybridization ratio<0.4, min over 4 timepoints (1-8 weeks)
in-vitro (glycerol) Griffin 2011 PPath non-essential M9 minimal+glycerol Gumbel 2 replicates; Padj<0.05
in-vitro (cholesterol) Griffin 2011 PPath non-essential M9 minimal+cholesterol Gumbel 3 replicates; Padj<0.05
differentially essential in cholesterol Griffin 2011 PPath NO (LFC=0.03) cholesterol vs glycerol resampling-SR YES if Padj<0.05, else not significant; LFC<0 means less insertions/more essential in cholesterol
in-vitro Smith 2022 eLife non-essential 7H9 HMM 6 replicates (raw data in Subramaniam 2017, PMID 31752678)
in-vivo (mice) Smith 2022 eLife non-essential BL6 mice HMM 6 replicates (raw data in Subramaniam 2017, PMID 31752678)
differentially essential in mice Smith 2022 eLife YES (LFC=-2.682) in-vivo vs in-vitro ZINB YES if Padj<0.05, else not significant; LFC<0 means less insertions/more essential in mice
in-vitro (minimal) Minato 2019 mSys non-essential minimal medium HMM
in-vitro (YM rich medium) Minato 2019 mSys non-essential YM rich medium HMM 7H9 supplemented with ~20 metabolites (amino acids, cofactors)
differentially essential in YM rich medium Minato 2019 mSys NO (LFC=-0.0) YM rich vs minimal medium resampling
Analysis of Positive Selection in Clinical Isolates
*new*
data from Culviner et al (2025) (55,259 Mtb clinical isolates)
overall pN/pS for Rv3876: 0.841395202
lineage-specific pN/pS in L1: 0.712936063
lineage-specific pN/pS in L2: 0.844654559
lineage-specific pN/pS in L3: 0.809209234
lineage-specific pN/pS in L4: 0.898845228
Analysis of dN/dS (omega) in a global collection of 10k Mtb clinical isolates using GenomegaMap (Window model)
clinical isolates collection: global set of 10,626 Mtb genomes
In the omega plots, the black line shows the mean estimate of omega (dN/dS) at each codon, and the blue lines are the bounds for the 95% credible interval (95%CI, from MCMC sampling).
A gene is under significant positive selection if the lower-bound of the 95%CI of omega (lower blue line) exceeds 1.0 at any codon.
global set of 10,626 Mtb clinical isolates
under significant positive selection? NO
omega peak height (95%CI lower bound) 1.4 (0.82)
codons under selection
omega plots
genetic variants* link
* example format for variants: "D27 (GAC): D27H (CAC,11)" means "Asp27 (native codon GAC) mutated to His (codon CAC) in 11 isolates"
BioCyc
Gene interactions based on ChIPSeq and Transcription Factor Over-Expression (TFOE) (Systems Biology )
NOTE:
see table of TFOE interactions below
Interactions based on ChIPSeq data
Binds To:
No bindings to other targets were found.
Bound By:
Binds To:
No bindings to other targets were found.
Bound By:
TFOE = Transcription Factor Over-Expression study
significance criteria used in paper: greater than 2-fold change (|LFC|>=1.0) and Padj<0.01
gene dysregulated by OE of LFC
Rv3876/espI Rv3862c/whiB6 1.46
Upregulates:
Does not upregulate other genes.
Upregulated by:
Downregulates:
Does not downregulate other genes.
Downregulated by:
Not downregulated by other genes.
