28LN image
Deposition Date 2026-02-05
Release Date 2026-06-10
Last Version Date 2026-06-24
Entry Detail
PDB ID:
28LN
Keywords:
Title:
XBP1u-stalled RPL4 RNC in complex with NAC
Biological Source:
Source Organism(s):
Homo sapiens (Taxon ID: 9606)
Expression System(s):
Method Details:
Experimental Method:
Resolution:
2.70 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polyribonucleotide
Molecule:18S rRNA
Chain IDs:ZA (auth: A2)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPSA
Chain IDs:AB (auth: AA)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S3a
Gene (Uniprot):RPS3A
Chain IDs:BB (auth: AB)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S2
Gene (Uniprot):RPS2
Chain IDs:CB (auth: AC)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S3
Gene (Uniprot):RPS3
Chain IDs:DB (auth: AD)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPS4X
Chain IDs:EB (auth: AE)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S5
Gene (Uniprot):RPS5
Chain IDs:FB (auth: AF)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S6
Gene (Uniprot):RPS6
Chain IDs:GB (auth: AG)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S7
Gene (Uniprot):RPS7
Chain IDs:HB (auth: AH)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S8
Gene (Uniprot):RPS8
Chain IDs:IB (auth: AI)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S9
Gene (Uniprot):RPS9
Chain IDs:JB (auth: AJ)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S10
Gene (Uniprot):RPS10
Chain IDs:KB (auth: AK)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPS11
Chain IDs:LB (auth: AL)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S12
Gene (Uniprot):RPS12
Chain IDs:MB (auth: AM)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S13
Gene (Uniprot):RPS13
Chain IDs:NB (auth: AN)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S14
Gene (Uniprot):RPS14
Chain IDs:OB (auth: AO)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S15
Gene (Uniprot):RPS15
Chain IDs:PB (auth: AP)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S16
Gene (Uniprot):RPS16
Chain IDs:QB (auth: AQ)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S17
Gene (Uniprot):RPS17
Chain IDs:RB (auth: AR)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPS18
Chain IDs:SB (auth: AS)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPS19
Chain IDs:TB (auth: AT)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S20
Gene (Uniprot):RPS20
Chain IDs:UB (auth: AU)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPS21
Chain IDs:VB (auth: AV)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S15a
Gene (Uniprot):RPS15A
Chain IDs:WB (auth: AW)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPS23
Chain IDs:XB (auth: AX)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S24
Gene (Uniprot):RPS24
Chain IDs:YB (auth: AY)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Small ribosomal subunit prote
Gene (Uniprot):RPS25
Chain IDs:ZB (auth: AZ)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S26
Gene (Uniprot):RPS26
Chain IDs:AC (auth: Aa)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S27
Gene (Uniprot):RPS27
Chain IDs:BC (auth: Ab)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S28
Gene (Uniprot):RPS28
Chain IDs:CC (auth: Ac)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:40S ribosomal protein S29
Gene (Uniprot):RPS29
Chain IDs:DC (auth: Ad)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Ubiquitin-like FUBI-ribosomal
Gene (Uniprot):FAU
Chain IDs:EC (auth: Ae)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Ubiquitin
Gene (Uniprot):RPS27A
Chain IDs:FC (auth: Af)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Receptor of activated protein
Gene (Uniprot):RACK1
Chain IDs:GC (auth: Ag)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L41
Gene (Uniprot):RPL41
Chain IDs:HC (auth: Ah)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):XBP1
Chain IDs:A (auth: B1)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Molecule:tRNA-Met-CAT
Chain IDs:B (auth: B2)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Molecule:mRNA fragment (6-MER)
Chain IDs:C (auth: B4)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Molecule:28S rRNA
Chain IDs:D (auth: B5)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Molecule:5S rRNA
Chain IDs:E (auth: B7)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polyribonucleotide
Molecule:5.8S rRNA
Chain IDs:F (auth: B8)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL8
Chain IDs:G (auth: BA)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL3
Chain IDs:H (auth: BB)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L4
Gene (Uniprot):RPL4
Chain IDs:I (auth: BC)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L5
Gene (Uniprot):RPL5
Chain IDs:J (auth: BD)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL6
Chain IDs:K (auth: BE)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL7
Chain IDs:L (auth: BF)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L7a
Gene (Uniprot):RPL7A
Chain IDs:M (auth: BG)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L9
Gene (Uniprot):RPL9, RPL9P7, RPL9P8, RPL9P9
Chain IDs:N (auth: BH)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L10
Gene (Uniprot):RPL10
Chain IDs:O (auth: BI)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L11
Gene (Uniprot):RPL11
Chain IDs:P (auth: BJ)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L13
Gene (Uniprot):RPL13
Chain IDs:Q (auth: BL)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L14
Gene (Uniprot):RPL14
Chain IDs:R (auth: BM)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L15
Gene (Uniprot):RPL15
Chain IDs:S (auth: BN)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L13a
Gene (Uniprot):RPL13A
Chain IDs:T (auth: BO)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L17
Gene (Uniprot):RPL17
Chain IDs:U (auth: BP)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L18
Gene (Uniprot):RPL18
Chain IDs:V (auth: BQ)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L19
Gene (Uniprot):RPL19
Chain IDs:W (auth: BR)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L18a
Gene (Uniprot):RPL18A
Chain IDs:X (auth: BS)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L21
Gene (Uniprot):RPL21
Chain IDs:Y (auth: BT)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L22
Gene (Uniprot):RPL22
Chain IDs:Z (auth: BU)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L23
Gene (Uniprot):RPL23
Chain IDs:AA (auth: BV)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L24
Gene (Uniprot):RPL24
Chain IDs:BA (auth: BW)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L23a
Gene (Uniprot):RPL23A
Chain IDs:CA (auth: BX)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L26
Gene (Uniprot):RPL26
Chain IDs:DA (auth: BY)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L27
Gene (Uniprot):RPL27
Chain IDs:EA (auth: BZ)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL27A
Chain IDs:FA (auth: Ba)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL29
Chain IDs:GA (auth: Bb)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L30
Gene (Uniprot):RPL30
Chain IDs:HA (auth: Bc)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L31
Gene (Uniprot):RPL31
Chain IDs:IA (auth: Bd)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L32
Gene (Uniprot):RPL32
Chain IDs:JA (auth: Be)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L35a
Gene (Uniprot):RPL35A
Chain IDs:KA (auth: Bf)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L34
Gene (Uniprot):RPL34
Chain IDs:LA (auth: Bg)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L35
Gene (Uniprot):RPL35
Chain IDs:MA (auth: Bh)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L36
Gene (Uniprot):RPL36
Chain IDs:NA (auth: Bi)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL37
Chain IDs:OA (auth: Bj)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L38
Gene (Uniprot):RPL38
Chain IDs:PA (auth: Bk)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L39
Gene (Uniprot):RPL39
Chain IDs:QA (auth: Bl)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Ubiquitin-60S ribosomal prote
Gene (Uniprot):UBA52
Chain IDs:RA (auth: Bm)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL36A
Chain IDs:SA (auth: Bo)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S ribosomal protein L37a
Gene (Uniprot):RPL37A
Chain IDs:TA (auth: Bp)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL28
Chain IDs:UA (auth: Br)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:60S acidic ribosomal protein
Gene (Uniprot):RPLP0
Chain IDs:VA (auth: Bs)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Large ribosomal subunit prote
Gene (Uniprot):RPL12
Chain IDs:WA (auth: Bt)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Nascent polypeptide-associate
Gene (Uniprot):NACA
Chain IDs:XA (auth: Bu)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Transcription factor BTF3
Gene (Uniprot):BTF3
Chain IDs:YA (auth: Bv)
Chain Length:0
Number of Molecules:1
Biological Source:Homo sapiens
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
GTP E G modified residue
HIC H HIS modified residue
HY3 XB PRO modified residue
MLZ GA LYS modified residue
NMM TB ARG modified residue
OMG F G modified residue
OMU F U modified residue
PSU F U modified residue
V5N G HIS modified residue
Primary Citation
NAC promotes co-translational protein folding at the ribosomal tunnel exit.
Mol.Cell 86 1311 1326.e11 (2026)
PMID: 41875886 DOI: 10.1016/j.molcel.2026.02.022

Abstact

The nascent polypeptide-associated complex (NAC) coordinates enzymatic modifications and membrane targeting of nascent chains during translation. While the role of NAC as a dynamic hub for other factors is well established, its direct role in co-translational folding is unclear. By proteome-wide profiling of co-translational NAC interactions in human cells, we found that NAC recognizes emerging segments enriched in hydrophobicity and alpha-helical propensity within folded domains of cytonuclear proteins. Single-molecule and structural analyses reveal that NAC, via its beta-barrel domain, dynamically interacts with nascent chains at the ribosomal tunnel exit and is capable of promoting on-pathway folding. Compartment-specific nascent chain interactions of NAC further elucidate its role in targeting to the endoplasmic reticulum and in mitochondrial membrane protein biogenesis. Together, these findings show that human NAC acts as a bona fide co-translational chaperone that directly promotes early protein folding at the ribosomal tunnel exit, expanding its functional repertoire in protein biogenesis.

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Primary Citation of related structures
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