This gene encodes a member of the hydroxymethylbilane synthase superfamily. The encoded protein is the third enzyme of the heme biosynthetic pathway and catalyzes the head to tail condensation of four porphobilinogen molecules into the linear hydroxymethylbilane. Mutations in this gene are associated with the autosomal dominant disease acute intermittent porphyria. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]
Transcription factors with Perturb-seq knockdown data for HMBS. The Binding column indicates whether any binding evidence exists for this TF–gene pair (ChIP-seq or motif footprint peaks). The Mean coef is the average Perturb-seq regression coefficient across active gRNAs (positive = HMBS upregulated upon KD; negative = downregulated). The Outlier column indicates whether this gene is in the top or bottom 5% of all TF knockdown effects.
| TF | Mean coef | Binding | Outlier | TF→Gene link |
|---|
Open chromatin peaks (ATAC-seq) in the genomic neighbourhood of HMBS, linked by TSS proximity or chromatin conformation (Multiome / HiCAR). Each element overlaps at least one TF ChIP-seq binding site — the TFs column shows how many distinct TFs bind that element.
| Accessibility | Element | Dist. to TSS | Link type | TFs |
|---|---|---|---|---|
| chr11:118,789,603–118,790,362 | 295.1 kb | Distal (>10kb) Multiome | 293 | |
| chr11:118,790,448–118,793,117 | 291.9 kb | Distal (>10kb) Multiome | 958 | |
| chr11:118,907,074–118,907,685 | 177.6 kb | Distal (>10kb) Multiome | 491 | |
| chr11:118,909,181–118,909,816 | 175.5 kb | Distal (>10kb) Multiome | 326 | |
| chr11:118,909,976–118,911,609 | 174.2 kb | Distal (>10kb) Multiome | 652 | |
| chr11:118,911,717–118,912,963 | 172.6 kb | Distal (>10kb) Multiome | 689 | |
| chr11:118,916,429–118,917,335 | 167.9 kb | Distal (>10kb) Multiome | 355 | |
| chr11:118,917,640–118,918,851 | 166.4 kb | Distal (>10kb) Multiome | 522 | |
| chr11:118,925,703–118,926,356 | 158.8 kb | Distal (>10kb) Multiome | 595 | |
| chr11:118,927,947–118,930,852 | 155.4 kb | Distal (>10kb) Multiome | 892 | |
| chr11:118,997,538–118,998,797 | 86.8 kb | Distal (>10kb) Multiome | 798 | |
| chr11:119,018,081–119,019,265 | 66.3 kb | Distal (>10kb) Multiome | 897 | |
| chr11:119,029,885–119,031,330 | 54.0 kb | Distal (>10kb) Multiome | 876 | |
| chr11:119,056,436–119,057,778 | 27.6 kb | Distal (>10kb) Multiome | 815 | |
| chr11:119,067,446–119,068,100 | 17.1 kb | Distal (>10kb) Multiome | 762 | |
| chr11:119,084,563–119,085,756 | 141 bp | At TSS Multiome | 846 | |
| chr11:119,093,969–119,096,070 | 10.7 kb | Distal (>10kb) Multiome | 1046 | |
| chr11:119,101,351–119,102,791 | 17.3 kb | Distal (>10kb) Multiome | 871 | |
| chr11:119,106,906–119,107,993 | 22.4 kb | Distal (>10kb) Multiome | 650 | |
| chr11:119,120,857–119,122,037 | 36.6 kb | Distal (>10kb) Multiome | 787 | |
| chr11:119,144,795–119,145,355 | 60.2 kb | Distal (>10kb) Multiome | 230 | |
| chr11:119,148,816–119,149,933 | 64.7 kb | Distal (>10kb) Multiome | 262 | |
| chr11:119,168,601–119,169,645 | 84.0 kb | Distal (>10kb) Multiome | 794 | |
| chr11:119,205,241–119,207,150 | 121.2 kb | Distal (>10kb) Multiome | 695 | |
| chr11:119,315,017–119,315,819 | 230.5 kb | Distal (>10kb) Multiome | 270 | |
| chr11:119,316,693–119,317,760 | 232.3 kb | Distal (>10kb) Multiome | 463 | |
| chr11:119,320,617–119,321,906 | 236.9 kb | Distal (>10kb) Multiome | 516 | |
| chr11:119,334,140–119,334,815 | 249.5 kb | Distal (>10kb) Multiome | 577 | |
| chr11:119,337,716–119,338,797 | 253.4 kb | Distal (>10kb) Multiome | 412 | |
| chr11:119,339,587–119,340,902 | 255.3 kb | Distal (>10kb) Multiome | 477 | |
| chr11:119,356,332–119,357,013 | 271.9 kb | Distal (>10kb) Multiome | 366 | |
| chr11:119,361,041–119,361,699 | 276.5 kb | Distal (>10kb) Multiome | 431 | |
| chr11:119,363,939–119,364,561 | 279.3 kb | Distal (>10kb) Multiome | 255 | |
| chr11:119,377,954–119,379,307 | 293.7 kb | Distal (>10kb) Multiome | 307 | |
| chr11:119,380,894–119,382,060 | 296.8 kb | Distal (>10kb) Multiome | 800 |
Genomic view of the HMBS locus showing ATAC-seq accessibility and RNA-seq expression across the ESC → DE time course, together with TF binding peaks and element-to-TSS loop connections.